CA2111761A1 - Shaped articles of graduated refractive index exhibiting low dispersion - Google Patents
Shaped articles of graduated refractive index exhibiting low dispersionInfo
- Publication number
- CA2111761A1 CA2111761A1 CA002111761A CA2111761A CA2111761A1 CA 2111761 A1 CA2111761 A1 CA 2111761A1 CA 002111761 A CA002111761 A CA 002111761A CA 2111761 A CA2111761 A CA 2111761A CA 2111761 A1 CA2111761 A1 CA 2111761A1
- Authority
- CA
- Canada
- Prior art keywords
- article
- polymer
- refractive index
- fluorinated
- guest molecule
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000006185 dispersion Substances 0.000 title claims 2
- 230000001747 exhibiting effect Effects 0.000 title claims 2
- 229920000642 polymer Polymers 0.000 claims abstract description 49
- 239000011159 matrix material Substances 0.000 claims abstract description 30
- 230000003287 optical effect Effects 0.000 claims abstract description 25
- 239000000835 fiber Substances 0.000 claims abstract description 17
- 229920001169 thermoplastic Polymers 0.000 claims abstract description 15
- 239000004416 thermosoftening plastic Substances 0.000 claims abstract description 15
- 230000000379 polymerizing effect Effects 0.000 claims abstract description 6
- 239000000178 monomer Substances 0.000 claims description 38
- 238000006116 polymerization reaction Methods 0.000 claims description 32
- 239000013308 plastic optical fiber Substances 0.000 claims description 24
- DOIRQSBPFJWKBE-UHFFFAOYSA-N dibutyl phthalate Chemical compound CCCCOC(=O)C1=CC=CC=C1C(=O)OCCCC DOIRQSBPFJWKBE-UHFFFAOYSA-N 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 18
- 239000013307 optical fiber Substances 0.000 claims description 15
- 229920002313 fluoropolymer Polymers 0.000 claims description 12
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 11
- -1 m-dichlorobenze Chemical compound 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 229910052805 deuterium Chemical group 0.000 claims description 9
- 229910052731 fluorine Inorganic materials 0.000 claims description 9
- 239000011737 fluorine Substances 0.000 claims description 8
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 5
- YZCKVEUIGOORGS-OUBTZVSYSA-N Deuterium Chemical group [2H] YZCKVEUIGOORGS-OUBTZVSYSA-N 0.000 claims description 5
- 239000000460 chlorine Substances 0.000 claims description 5
- 229910052801 chlorine Inorganic materials 0.000 claims description 5
- 229960002380 dibutyl phthalate Drugs 0.000 claims description 5
- 229910052739 hydrogen Inorganic materials 0.000 claims description 5
- 239000001257 hydrogen Substances 0.000 claims description 5
- RFFLAFLAYFXFSW-UHFFFAOYSA-N 1,2-dichlorobenzene Chemical compound ClC1=CC=CC=C1Cl RFFLAFLAYFXFSW-UHFFFAOYSA-N 0.000 claims description 4
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 claims description 4
- SESFRYSPDFLNCH-UHFFFAOYSA-N benzyl benzoate Chemical compound C=1C=CC=CC=1C(=O)OCC1=CC=CC=C1 SESFRYSPDFLNCH-UHFFFAOYSA-N 0.000 claims description 4
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 150000001975 deuterium Chemical group 0.000 claims description 4
- 230000008569 process Effects 0.000 claims description 4
- 125000004122 cyclic group Chemical group 0.000 claims description 3
- 230000001419 dependent effect Effects 0.000 claims description 3
- 230000000977 initiatory effect Effects 0.000 claims description 3
- WWINNZWDOWZBFV-UHFFFAOYSA-N 1-(1-methoxycyclohexa-2,4-dien-1-yl)ethylbenzene Chemical compound C=1C=CC=CC=1C(C)C1(OC)CC=CC=C1 WWINNZWDOWZBFV-UHFFFAOYSA-N 0.000 claims description 2
- ZXEWECPOIXUDES-UHFFFAOYSA-N 1-o-butyl 2-o-phenyl benzene-1,2-dicarboxylate Chemical compound CCCCOC(=O)C1=CC=CC=C1C(=O)OC1=CC=CC=C1 ZXEWECPOIXUDES-UHFFFAOYSA-N 0.000 claims description 2
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 claims description 2
- IRIAEXORFWYRCZ-UHFFFAOYSA-N Butylbenzyl phthalate Chemical compound CCCCOC(=O)C1=CC=CC=C1C(=O)OCC1=CC=CC=C1 IRIAEXORFWYRCZ-UHFFFAOYSA-N 0.000 claims description 2
- 229960002903 benzyl benzoate Drugs 0.000 claims description 2
- 150000002431 hydrogen Chemical group 0.000 claims description 2
- KKEYFWRCBNTPAC-UHFFFAOYSA-L terephthalate(2-) Chemical compound [O-]C(=O)C1=CC=C(C([O-])=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-L 0.000 claims description 2
- 125000004169 (C1-C6) alkyl group Chemical group 0.000 claims 4
- 125000000041 C6-C10 aryl group Chemical group 0.000 claims 3
- VAJVDSVGBWFCLW-UHFFFAOYSA-N 3-Phenyl-1-propanol Chemical compound OCCCC1=CC=CC=C1 VAJVDSVGBWFCLW-UHFFFAOYSA-N 0.000 claims 2
- QARVLSVVCXYDNA-UHFFFAOYSA-N bromobenzene Chemical compound BrC1=CC=CC=C1 QARVLSVVCXYDNA-UHFFFAOYSA-N 0.000 claims 2
- 125000000008 (C1-C10) alkyl group Chemical group 0.000 claims 1
- PAAZPARNPHGIKF-UHFFFAOYSA-N 1,2-dibromoethane Chemical compound BrCCBr PAAZPARNPHGIKF-UHFFFAOYSA-N 0.000 claims 1
- 150000001491 aromatic compounds Chemical class 0.000 claims 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 claims 1
- 229910052794 bromium Inorganic materials 0.000 claims 1
- 230000000694 effects Effects 0.000 claims 1
- 238000005253 cladding Methods 0.000 description 20
- 239000011162 core material Substances 0.000 description 15
- 239000000203 mixture Substances 0.000 description 15
- 239000000463 material Substances 0.000 description 11
- 239000003999 initiator Substances 0.000 description 10
- 150000002500 ions Chemical class 0.000 description 10
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 9
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 9
- 239000002253 acid Substances 0.000 description 9
- 238000009826 distribution Methods 0.000 description 9
- 150000001875 compounds Chemical class 0.000 description 8
- 125000003118 aryl group Chemical group 0.000 description 6
- 125000004429 atom Chemical group 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 239000000499 gel Substances 0.000 description 6
- 239000011521 glass Substances 0.000 description 6
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 5
- 125000000217 alkyl group Chemical group 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- 150000003254 radicals Chemical class 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- IZUPBVBPLAPZRR-UHFFFAOYSA-N pentachlorophenol Chemical compound OC1=C(Cl)C(Cl)=C(Cl)C(Cl)=C1Cl IZUPBVBPLAPZRR-UHFFFAOYSA-N 0.000 description 4
- 150000003384 small molecules Chemical class 0.000 description 4
- 238000001228 spectrum Methods 0.000 description 4
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 4
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 3
- BTANRVKWQNVYAZ-UHFFFAOYSA-N 2-butanol Substances CCC(C)O BTANRVKWQNVYAZ-UHFFFAOYSA-N 0.000 description 3
- 239000004342 Benzoyl peroxide Substances 0.000 description 3
- WVDDGKGOMKODPV-UHFFFAOYSA-N Benzyl alcohol Chemical compound OCC1=CC=CC=C1 WVDDGKGOMKODPV-UHFFFAOYSA-N 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- AYFVYJQAPQTCCC-GBXIJSLDSA-N L-threonine Chemical compound C[C@@H](O)[C@H](N)C(O)=O AYFVYJQAPQTCCC-GBXIJSLDSA-N 0.000 description 3
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 230000000996 additive effect Effects 0.000 description 3
- 235000019400 benzoyl peroxide Nutrition 0.000 description 3
- WNAHIZMDSQCWRP-UHFFFAOYSA-N dodecane-1-thiol Chemical compound CCCCCCCCCCCCS WNAHIZMDSQCWRP-UHFFFAOYSA-N 0.000 description 3
- 150000002148 esters Chemical class 0.000 description 3
- 125000001153 fluoro group Chemical group F* 0.000 description 3
- RMVRSNDYEFQCLF-UHFFFAOYSA-N thiophenol Chemical compound SC1=CC=CC=C1 RMVRSNDYEFQCLF-UHFFFAOYSA-N 0.000 description 3
- XBNGYFFABRKICK-UHFFFAOYSA-N 2,3,4,5,6-pentafluorophenol Chemical group OC1=C(F)C(F)=C(F)C(F)=C1F XBNGYFFABRKICK-UHFFFAOYSA-N 0.000 description 2
- OZAIFHULBGXAKX-VAWYXSNFSA-N AIBN Substances N#CC(C)(C)\N=N\C(C)(C)C#N OZAIFHULBGXAKX-VAWYXSNFSA-N 0.000 description 2
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 2
- LFVLUOAHQIVABZ-UHFFFAOYSA-N Iodofenphos Chemical compound COP(=S)(OC)OC1=CC(Cl)=C(I)C=C1Cl LFVLUOAHQIVABZ-UHFFFAOYSA-N 0.000 description 2
- 101100400378 Mus musculus Marveld2 gene Proteins 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 125000002723 alicyclic group Chemical group 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 239000012986 chain transfer agent Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- SURLGNKAQXKNSP-DBLYXWCISA-N chlorin Chemical compound C\1=C/2\N/C(=C\C3=N/C(=C\C=4NC(/C=C\5/C=CC/1=N/5)=CC=4)/C=C3)/CC\2 SURLGNKAQXKNSP-DBLYXWCISA-N 0.000 description 2
- 230000002844 continuous effect Effects 0.000 description 2
- 238000007334 copolymerization reaction Methods 0.000 description 2
- XCIXKGXIYUWCLL-UHFFFAOYSA-N cyclopentanol Chemical compound OC1CCCC1 XCIXKGXIYUWCLL-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- ZSIAUFGUXNUGDI-UHFFFAOYSA-N hexan-1-ol Chemical compound CCCCCCO ZSIAUFGUXNUGDI-UHFFFAOYSA-N 0.000 description 2
- 229920001519 homopolymer Polymers 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- SUVIGLJNEAMWEG-UHFFFAOYSA-N propane-1-thiol Chemical compound CCCS SUVIGLJNEAMWEG-UHFFFAOYSA-N 0.000 description 2
- 239000011541 reaction mixture Substances 0.000 description 2
- 230000009257 reactivity Effects 0.000 description 2
- IOVGROKTTNBUGK-SJCJKPOMSA-N ritodrine Chemical compound N([C@@H](C)[C@H](O)C=1C=CC(O)=CC=1)CCC1=CC=C(O)C=C1 IOVGROKTTNBUGK-SJCJKPOMSA-N 0.000 description 2
- CWERGRDVMFNCDR-UHFFFAOYSA-N thioglycolic acid Chemical compound OC(=O)CS CWERGRDVMFNCDR-UHFFFAOYSA-N 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- HGTUJZTUQFXBIH-UHFFFAOYSA-N (2,3-dimethyl-3-phenylbutan-2-yl)benzene Chemical group C=1C=CC=CC=1C(C)(C)C(C)(C)C1=CC=CC=C1 HGTUJZTUQFXBIH-UHFFFAOYSA-N 0.000 description 1
- BHMLFPOTZYRDKA-IRXDYDNUSA-N (2s)-2-[(s)-(2-iodophenoxy)-phenylmethyl]morpholine Chemical compound IC1=CC=CC=C1O[C@@H](C=1C=CC=CC=1)[C@H]1OCCNC1 BHMLFPOTZYRDKA-IRXDYDNUSA-N 0.000 description 1
- DNIAPMSPPWPWGF-GSVOUGTGSA-N (R)-(-)-Propylene glycol Chemical compound C[C@@H](O)CO DNIAPMSPPWPWGF-GSVOUGTGSA-N 0.000 description 1
- LLCKXLBGFBTDHO-UPHRSURJSA-N (z)-2,3-difluoroprop-2-enoic acid Chemical compound OC(=O)C(\F)=C\F LLCKXLBGFBTDHO-UPHRSURJSA-N 0.000 description 1
- BYEAHWXPCBROCE-UHFFFAOYSA-N 1,1,1,3,3,3-hexafluoropropan-2-ol Chemical class FC(F)(F)C(O)C(F)(F)F BYEAHWXPCBROCE-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-ZBJDZAJPSA-N 1,1,2,2,2-pentadeuterioethanol Chemical compound [2H]C([2H])([2H])C([2H])([2H])O LFQSCWFLJHTTHZ-ZBJDZAJPSA-N 0.000 description 1
- DZMADYFTYWAMKS-UHFFFAOYSA-N 1,2,2,3,3,4,4,5,5-nonachlorocyclopentan-1-ol Chemical compound OC1(Cl)C(Cl)(Cl)C(Cl)(Cl)C(Cl)(Cl)C1(Cl)Cl DZMADYFTYWAMKS-UHFFFAOYSA-N 0.000 description 1
- AYMDJPGTQFHDSA-UHFFFAOYSA-N 1-(2-ethenoxyethoxy)-2-ethoxyethane Chemical compound CCOCCOCCOC=C AYMDJPGTQFHDSA-UHFFFAOYSA-N 0.000 description 1
- ADSSRVFBKWVCPI-UHFFFAOYSA-N 1-cycloheptyl-3,3,4,4-tetrafluorocycloheptan-1-ol Chemical compound C1CCCCCC1C1(O)CCCC(F)(F)C(F)(F)C1 ADSSRVFBKWVCPI-UHFFFAOYSA-N 0.000 description 1
- HKHNEYTWGKNLFX-UHFFFAOYSA-N 2,3,3,4,4,5-hexachloro-1-(cyclohepten-1-yl)cycloheptene Chemical group ClC1(Cl)C(Cl)(Cl)C(Cl)CCC(C=2CCCCCC=2)=C1Cl HKHNEYTWGKNLFX-UHFFFAOYSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- TYCFGHUTYSLISP-UHFFFAOYSA-N 2-fluoroprop-2-enoic acid Chemical compound OC(=O)C(F)=C TYCFGHUTYSLISP-UHFFFAOYSA-N 0.000 description 1
- AXUYQDCVKHKQOW-UHFFFAOYSA-N 2-fluoropropan-2-ol Chemical compound CC(C)(O)F AXUYQDCVKHKQOW-UHFFFAOYSA-N 0.000 description 1
- ISUXQQTXICTKOV-UHFFFAOYSA-N 2-methylpentane-2-thiol Chemical compound CCCC(C)(C)S ISUXQQTXICTKOV-UHFFFAOYSA-N 0.000 description 1
- JBTDFRNUVWFUGL-UHFFFAOYSA-N 3-aminopropyl carbamimidothioate;dihydrobromide Chemical compound Br.Br.NCCCSC(N)=N JBTDFRNUVWFUGL-UHFFFAOYSA-N 0.000 description 1
- CWILBCHQQLFUSC-ZPJDWWTCSA-N 4-cycloheptyl-4-deuteriooxy-1,2-difluoro-1,2-bis(trifluoromethyl)cycloheptane Chemical compound FC1(CCCC(CC1(C(F)(F)F)F)(C1CCCCCC1)O[2H])C(F)(F)F CWILBCHQQLFUSC-ZPJDWWTCSA-N 0.000 description 1
- OPPHXULEHGYZRW-UHFFFAOYSA-N 4-methoxy-2,4-dimethyl-2-phenyldiazenylpentanenitrile Chemical compound COC(C)(C)CC(C)(C#N)N=NC1=CC=CC=C1 OPPHXULEHGYZRW-UHFFFAOYSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 235000007319 Avena orientalis Nutrition 0.000 description 1
- 244000075850 Avena orientalis Species 0.000 description 1
- 241000937413 Axia Species 0.000 description 1
- 241000905957 Channa melasoma Species 0.000 description 1
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- 101100536354 Drosophila melanogaster tant gene Proteins 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 206010056740 Genital discharge Diseases 0.000 description 1
- 241001364889 Helius Species 0.000 description 1
- 101000992283 Homo sapiens Optineurin Proteins 0.000 description 1
- HOKDBMAJZXIPGC-UHFFFAOYSA-N Mequitazine Chemical compound C12=CC=CC=C2SC2=CC=CC=C2N1CC1C(CC2)CCN2C1 HOKDBMAJZXIPGC-UHFFFAOYSA-N 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-M Methacrylate Chemical compound CC(=C)C([O-])=O CERQOIWHTDAKMF-UHFFFAOYSA-M 0.000 description 1
- 102100031822 Optineurin Human genes 0.000 description 1
- 101150014691 PPARA gene Proteins 0.000 description 1
- 241000610375 Sparisoma viride Species 0.000 description 1
- 241000950638 Symphysodon discus Species 0.000 description 1
- 101150007148 THI5 gene Proteins 0.000 description 1
- 244000166490 Tetrameles nudiflora Species 0.000 description 1
- 241000613130 Tima Species 0.000 description 1
- 241000289690 Xenarthra Species 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- YVPYQUNUQOZFHG-UHFFFAOYSA-N amidotrizoic acid Chemical compound CC(=O)NC1=C(I)C(NC(C)=O)=C(I)C(C(O)=O)=C1I YVPYQUNUQOZFHG-UHFFFAOYSA-N 0.000 description 1
- 101150008413 atoD gene Proteins 0.000 description 1
- 235000019445 benzyl alcohol Nutrition 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 125000001246 bromo group Chemical group Br* 0.000 description 1
- WQAQPCDUOCURKW-UHFFFAOYSA-N butanethiol Chemical compound CCCCS WQAQPCDUOCURKW-UHFFFAOYSA-N 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- GPUADMRJQVPIAS-QCVDVZFFSA-M cerivastatin sodium Chemical compound [Na+].COCC1=C(C(C)C)N=C(C(C)C)C(\C=C\[C@@H](O)C[C@@H](O)CC([O-])=O)=C1C1=CC=C(F)C=C1 GPUADMRJQVPIAS-QCVDVZFFSA-M 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- HPXRVTGHNJAIIH-UHFFFAOYSA-N cyclohexanol Chemical compound OC1CCCCC1 HPXRVTGHNJAIIH-UHFFFAOYSA-N 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000005695 dehalogenation reaction Methods 0.000 description 1
- 230000000779 depleting effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- SUPCQIBBMFXVTL-UHFFFAOYSA-N ethyl 2-methylprop-2-enoate Chemical compound CCOC(=O)C(C)=C SUPCQIBBMFXVTL-UHFFFAOYSA-N 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- PYGSKMBEVAICCR-UHFFFAOYSA-N hexa-1,5-diene Chemical group C=CCCC=C PYGSKMBEVAICCR-UHFFFAOYSA-N 0.000 description 1
- OCYSGIYOVXAGKQ-UHFFFAOYSA-N hydron;3-[1-hydroxy-2-(methylamino)ethyl]phenol;chloride Chemical compound Cl.CNCC(O)C1=CC=CC(O)=C1 OCYSGIYOVXAGKQ-UHFFFAOYSA-N 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- RGXCTRIQQODGIZ-UHFFFAOYSA-O isodesmosine Chemical compound OC(=O)C(N)CCCC[N+]1=CC(CCC(N)C(O)=O)=CC(CCC(N)C(O)=O)=C1CCCC(N)C(O)=O RGXCTRIQQODGIZ-UHFFFAOYSA-O 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 125000005641 methacryl group Chemical group 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000010137 moulding (plastic) Methods 0.000 description 1
- 150000001451 organic peroxides Chemical class 0.000 description 1
- 229920000620 organic polymer Polymers 0.000 description 1
- SVHOVVJFOWGYJO-UHFFFAOYSA-N pentabromophenol Chemical compound OC1=C(Br)C(Br)=C(Br)C(Br)=C1Br SVHOVVJFOWGYJO-UHFFFAOYSA-N 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 150000002978 peroxides Chemical class 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000010526 radical polymerization reaction Methods 0.000 description 1
- 230000002226 simultaneous effect Effects 0.000 description 1
- ACXGJHCPFCFILV-UHFFFAOYSA-M sodium;2-(4-chloro-2-methylphenoxy)acetate;3,6-dichloro-2-methoxybenzoic acid Chemical compound [Na+].COC1=C(Cl)C=CC(Cl)=C1C(O)=O.CC1=CC(Cl)=CC=C1OCC([O-])=O ACXGJHCPFCFILV-UHFFFAOYSA-M 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- KDYFGRWQOYBRFD-UHFFFAOYSA-N succinic acid Chemical compound OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- WMXCDAVJEZZYLT-UHFFFAOYSA-N tert-butylthiol Chemical compound CC(C)(C)S WMXCDAVJEZZYLT-UHFFFAOYSA-N 0.000 description 1
- 238000012719 thermal polymerization Methods 0.000 description 1
- 238000009757 thermoplastic moulding Methods 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- CWERGRDVMFNCDR-UHFFFAOYSA-M thioglycolate(1-) Chemical compound [O-]C(=O)CS CWERGRDVMFNCDR-UHFFFAOYSA-M 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- 229920006352 transparent thermoplastic Polymers 0.000 description 1
- OKKJLVBELUTLKV-FIBGUPNXSA-N trideuteriomethanol Chemical compound [2H]C([2H])([2H])O OKKJLVBELUTLKV-FIBGUPNXSA-N 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- NWONKYPBYAMBJT-UHFFFAOYSA-L zinc sulfate Chemical compound [Zn+2].[O-]S([O-])(=O)=O NWONKYPBYAMBJT-UHFFFAOYSA-L 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02033—Core or cladding made from organic material, e.g. polymeric material
- G02B6/02038—Core or cladding made from organic material, e.g. polymeric material with core or cladding having graded refractive index
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
- B29C67/24—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 characterised by the choice of material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D11/00—Producing optical elements, e.g. lenses or prisms
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D11/00—Producing optical elements, e.g. lenses or prisms
- B29D11/00663—Production of light guides
- B29D11/00721—Production of light guides involving preforms for the manufacture of light guides
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
- C08L33/04—Homopolymers or copolymers of esters
- C08L33/14—Homopolymers or copolymers of esters of esters containing halogen, nitrogen, sulfur, or oxygen atoms in addition to the carboxy oxygen
- C08L33/16—Homopolymers or copolymers of esters containing halogen atoms
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
- G02B1/045—Light guides
- G02B1/046—Light guides characterised by the core material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
- B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2011/00—Optical elements, e.g. lenses, prisms
- B29L2011/0016—Lenses
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2011/00—Optical elements, e.g. lenses, prisms
- B29L2011/0075—Light guides, optical cables
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Abstract
ABSTRACT
A monolithic, thermoplastic article with a continuously graded refractive index is formed by polymerizing a fluorinated matrix polymer in the presence of a low molecular weight, substantially unreactive guest molecule of different refractive index than the matrix polymer. The thermoplastic articles may be used to produce shaped articles such as optical waveguides, fibers or lenses of low attenuation and high bandwidth.
A monolithic, thermoplastic article with a continuously graded refractive index is formed by polymerizing a fluorinated matrix polymer in the presence of a low molecular weight, substantially unreactive guest molecule of different refractive index than the matrix polymer. The thermoplastic articles may be used to produce shaped articles such as optical waveguides, fibers or lenses of low attenuation and high bandwidth.
Description
117fi~
~AP~D aR~ J8 0~ ~RAD~A~D ~BPRACT~V~ ~NDES
~IBI~N~ LO~ D~8~RS~ON
TECHN.ICA~ FIELD
The present invention r~lat~s to optical materials o~ the graded ind~x typ~ form-d from ~ low attenuation ~luorinatsd polym-r host ~atrlx/~m~ll guest molacule prefor~. ~ha pr~for~ i~ polymarized ~ro~ n matrix/guest molecul~ mixture ~o that a ~table concentration and re~ractive index gradient is established in the preform. Optical material~ having.a graduated refractive index, ~uch afi optical ~ibers are produced from the preforms.
BACXGROUND OF THE_I~YENTIO~
The desirabl~ propertie~ o~ a long distanc~transmitter optical fibsr includ~ flexibility, low signal attenuation, and ~inimal phase ~hi~t. Fib~r opti~
waveguides usually consist of a core material ~nd a .
tube/clad ma~erial with di~erent indices c~ re~raction.
In order to achiav~ long transmis~ion distanc2~ of light signals, the core and tube/clad ~at~rial should absorb a8 ~5 little light as pos~ible, and tho core material ~hould have a higher index o~ refraction than th~ tubelclad. ~n addition to th~ cor~ and cladding construction Or fiber~
graded index opt~cal material~ are ~180 k;nown in th~ art.
Grad~d indQx ~ib~r~ ~av~ a r-l~tively higher refraotive index in the center cor~ area which decrea~es I gradually and radially rrom the ce~t~r ax~3 ou~ward.
¦ Prior art g~aded index optic~l material~ w~r~ o~t~n ~orm~d ~rom inorganic optic~l ~ub~trate material~, ~uch ~ glas~, by doping the ~ubstr~t~ w~th ionic zubstances by ion exchange or other method~. Gr~duat~d ind~x (~GRINn) optical material~ havQ also bQ-n produc¢d from . , .
-` 21~ lfil organic polymer ~aterials by using various methods each of which contain~ inherent problem~.
Copolymerization 16 used to produce GRIN
optical article~ from two or more typ~ of monomers oi different react~vitie~. The relative proportion of monomer units per polymer i~ de~igned to vary Prom that of the early polymerization per~od to that of the late polymerization period in order to produc~ a reXractive index which is different between the cor~ and periphery of the article.
An example of copoly~erization i8 United State~
Patent No. 4,521,351 which discloses a method of making a preform for drawing into an optical fiber by way of polymerizing a mixtur~ of at l~ast thre~ vinyl monom~rs having different reactivities. m e mixture i8 put into a container of appropriate shape and the reaction is initiated at the outside ~urface. Due to diffsrent reaction rates, a polymeric article i~ form~d having gradients of the mono~eric constituonts 80 that ~
graduated index i~ achieved. A typical three component mixture includes methyl methacrylate, vinyl ~enzoate and vinyl phenylacetate. The mixtur~ mu~t exhibit ~oth appropriate reactivitie~ and upon polymerization, the desired rQfractive propertie~.
In copolymerization, however, the probl~m arises that t~e ~onomers o~ ~lower reactivity compounds may remain independent or incomplete in~t~ad of linking as a copolym~r. Th~ filOWly rQactive monomer~ may therefore contribut~ to change~ of th~ optical el~ent~
and render product~ such as waveguide~ les~ transparent.
An alternative production method for producing an organic poly~er refractiv- gradient ind~x product i~
directed to diffu~ion o~, ~wo or mor~ different type~ Or monom~r through a pr~polymer matrix. At fir~t, under heat or U.V. light the polymer precursor or prepolymer gel o~ a fir~t monomer rorms a tran~parent bridge structure or matrix of a desirably low refractivQ index.
~. . . . ~ ~ . .
7 ~ :~
~AP~D aR~ J8 0~ ~RAD~A~D ~BPRACT~V~ ~NDES
~IBI~N~ LO~ D~8~RS~ON
TECHN.ICA~ FIELD
The present invention r~lat~s to optical materials o~ the graded ind~x typ~ form-d from ~ low attenuation ~luorinatsd polym-r host ~atrlx/~m~ll guest molacule prefor~. ~ha pr~for~ i~ polymarized ~ro~ n matrix/guest molecul~ mixture ~o that a ~table concentration and re~ractive index gradient is established in the preform. Optical material~ having.a graduated refractive index, ~uch afi optical ~ibers are produced from the preforms.
BACXGROUND OF THE_I~YENTIO~
The desirabl~ propertie~ o~ a long distanc~transmitter optical fibsr includ~ flexibility, low signal attenuation, and ~inimal phase ~hi~t. Fib~r opti~
waveguides usually consist of a core material ~nd a .
tube/clad ma~erial with di~erent indices c~ re~raction.
In order to achiav~ long transmis~ion distanc2~ of light signals, the core and tube/clad ~at~rial should absorb a8 ~5 little light as pos~ible, and tho core material ~hould have a higher index o~ refraction than th~ tubelclad. ~n addition to th~ cor~ and cladding construction Or fiber~
graded index opt~cal material~ are ~180 k;nown in th~ art.
Grad~d indQx ~ib~r~ ~av~ a r-l~tively higher refraotive index in the center cor~ area which decrea~es I gradually and radially rrom the ce~t~r ax~3 ou~ward.
¦ Prior art g~aded index optic~l material~ w~r~ o~t~n ~orm~d ~rom inorganic optic~l ~ub~trate material~, ~uch ~ glas~, by doping the ~ubstr~t~ w~th ionic zubstances by ion exchange or other method~. Gr~duat~d ind~x (~GRINn) optical material~ havQ also bQ-n produc¢d from . , .
-` 21~ lfil organic polymer ~aterials by using various methods each of which contain~ inherent problem~.
Copolymerization 16 used to produce GRIN
optical article~ from two or more typ~ of monomers oi different react~vitie~. The relative proportion of monomer units per polymer i~ de~igned to vary Prom that of the early polymerization per~od to that of the late polymerization period in order to produc~ a reXractive index which is different between the cor~ and periphery of the article.
An example of copoly~erization i8 United State~
Patent No. 4,521,351 which discloses a method of making a preform for drawing into an optical fiber by way of polymerizing a mixtur~ of at l~ast thre~ vinyl monom~rs having different reactivities. m e mixture i8 put into a container of appropriate shape and the reaction is initiated at the outside ~urface. Due to diffsrent reaction rates, a polymeric article i~ form~d having gradients of the mono~eric constituonts 80 that ~
graduated index i~ achieved. A typical three component mixture includes methyl methacrylate, vinyl ~enzoate and vinyl phenylacetate. The mixtur~ mu~t exhibit ~oth appropriate reactivitie~ and upon polymerization, the desired rQfractive propertie~.
In copolymerization, however, the probl~m arises that t~e ~onomers o~ ~lower reactivity compounds may remain independent or incomplete in~t~ad of linking as a copolym~r. Th~ filOWly rQactive monomer~ may therefore contribut~ to change~ of th~ optical el~ent~
and render product~ such as waveguide~ les~ transparent.
An alternative production method for producing an organic poly~er refractiv- gradient ind~x product i~
directed to diffu~ion o~, ~wo or mor~ different type~ Or monom~r through a pr~polymer matrix. At fir~t, under heat or U.V. light the polymer precursor or prepolymer gel o~ a fir~t monomer rorms a tran~parent bridge structure or matrix of a desirably low refractivQ index.
~. . . . ~ ~ . .
7 ~ :~
Monomers are ~llowed to diffuse through the gel in a manner dependent on their particular mobility, and are then polymerized to form a polymer of graded refractive index. The graded index in this method varies ~ccording to the ratio of concentration of unreacted ~onomer in the gel to the conce~tration of mono~er.
For example, Un$t2d Stat~s ~at~nt 3,955,015 teaches a method of ~king a polymeric articl~ in~luding the ~tQps of: (1) p~rt~lly polymer$zing a network polymer ~uch as diallyl phthalata so that it i~ partially insoluble; (2) ~haping the article; (3) applying a ~econd monomer (methyl meth~crylate) to the ~urfac~ o~ th~
article 50 formed ~uch that it diffus~a inwardly, followed by (4) completing poly~erization of th~ second monomer within th~ network polymQr. Matarial~ are ~elected and diffu~ion i~ carri-~ out so that ~n ind2x gradient is created by way of compositional variance.
In thi~ diffu~ion typ~ proc~s~ it i~ difficult to control the conditions Or poly~ri~ation 80 that monomer diffusion r~ul~s in a ~uffici~ntly graded distribution of refraction indices. Noreover, poly~er gels or precursors produced ~rom di~ferent polyfunctional monomers exhibit varied phy~ical characteristic~ during heat-stretching or drawing to a long optical wav~guids or fiber which may léad to und~sir~bl~ guality defdGts.
Tha pra~ent im ~tion i~ ther~forQ dir~ct~d to a ~ynthetic pla~tic having ~ graded r¢fractiv~ in~ox distribution form~d by polymerizing z b~s~c matrix mono~er in the pre~enc- o~ a 6m~11 unreactive gue~t molecule that does not participat~ in th~ poly~erization.
SUMMARY OF THE INV~NTIO~
In accordance with the pr~sent invention, ~
~h~ped article o~ graduated rQ~ractiv~ lndex is formed ~y polymerizing ~ fluorinsted monomeric sy~te~ to ~or~ a matrix polymer in th~ pres~nce o~ a ~ub~tantially ~r; . : ~ J : : .. :; ~ .~ ~ . : . - : .
-- 21~17~ ~
For example, Un$t2d Stat~s ~at~nt 3,955,015 teaches a method of ~king a polymeric articl~ in~luding the ~tQps of: (1) p~rt~lly polymer$zing a network polymer ~uch as diallyl phthalata so that it i~ partially insoluble; (2) ~haping the article; (3) applying a ~econd monomer (methyl meth~crylate) to the ~urfac~ o~ th~
article 50 formed ~uch that it diffus~a inwardly, followed by (4) completing poly~erization of th~ second monomer within th~ network polymQr. Matarial~ are ~elected and diffu~ion i~ carri-~ out so that ~n ind2x gradient is created by way of compositional variance.
In thi~ diffu~ion typ~ proc~s~ it i~ difficult to control the conditions Or poly~ri~ation 80 that monomer diffusion r~ul~s in a ~uffici~ntly graded distribution of refraction indices. Noreover, poly~er gels or precursors produced ~rom di~ferent polyfunctional monomers exhibit varied phy~ical characteristic~ during heat-stretching or drawing to a long optical wav~guids or fiber which may léad to und~sir~bl~ guality defdGts.
Tha pra~ent im ~tion i~ ther~forQ dir~ct~d to a ~ynthetic pla~tic having ~ graded r¢fractiv~ in~ox distribution form~d by polymerizing z b~s~c matrix mono~er in the pre~enc- o~ a 6m~11 unreactive gue~t molecule that does not participat~ in th~ poly~erization.
SUMMARY OF THE INV~NTIO~
In accordance with the pr~sent invention, ~
~h~ped article o~ graduated rQ~ractiv~ lndex is formed ~y polymerizing ~ fluorinsted monomeric sy~te~ to ~or~ a matrix polymer in th~ pres~nce o~ a ~ub~tantially ~r; . : ~ J : : .. :; ~ .~ ~ . : . - : .
-- 21~17~ ~
unreactive low molecular weight compound. ~he low molecular weight compound or guest molecule has a different refractive index than the matrix polymer form~d }~ i~ ~nd i~ ~oluble in the ~luorinated monomer ~nd matrix polymer.
Poly~erization is ~nitiated ~t a ~urface o~ the polymerization ve~sel ~nd as polymerization progresses, the 6ubstantially unr~active compound di~fuses within the article toward~ the cent~r or cor~ go that ~ re~ractiv~
index gradient in a specific direction i~ obtained. The refractive index of the shap~d nrticles ~f the present invention is continuou~ly and radially vari~d from the center of the shaped article. The preferred difference in re~ractive index between the core and periphery of the article is ~t least 0.001.
The ~haped article may be rormed by u~ing a container tube a~ the polymQriz~tion reactor to produce the monolithic article. Alternatively the tube reactor is first used to produce ~ cladding polymer re~ction tube, which cladding in turn serves a~ the polymerization vessel and beco~e~ a part o~ the monolithic article upon completion of the reaction. In 6uch a process, the polymer of the cladding tube must expand as a gel in the presence o~ the core ~atrix monomer and must be ~t laa~t partially solubl~ therein. A$ the inner polymer wall of the polymer cont~iner 6~ells and partially dissolv~ in the monom~ric csre ~ixture plac~d in6ide the polym~r container, the corQ monomer ~imultnneously undergo~
succ~siva polymerization. The polymeri~ation occurs morQ rapidly in th~ gsl stat~ Or th~ inn~r wall o~ thQ
contain6r. As the poly~erization proc~ds, the unreactive guest molecule ccmponent migr~te~ toward th~
center of the article. After the polymerization ha~ b~en completed the concentration gradient of the unr~active ~ -high refractive index component i~ continuou~ly incr~asing ~rom the periphery~ to the core area of the 2 ,1. ~ & 1 polymeric ~onolithic body. The refractive index profile of the article is also pr~sent a3 a gr~dient.
Articles ~uch as an optically tran~parent poly~eric preform rod having a gradient refrective index produced by thi6 method are suitabl~ for hot-strotching into optical wave guide~ or fiber e~bodiments which retain a proportion~te di~tribution of refractiv~
ind:ces.
The pre~ent inv~ntion al~o concern~ A process for the fabrication of monolithic tran~par~nt th~rmo-plastic moldings or shaped Article~ comprising tbe step~
of (a) forming an outer shaped portion, ~uch as ~ '.ube of cylindrical dimensions, by radically polymeriz~ng a fluorinated monomeric system in a 6uitable vessel;
lS (b) forming a central portion within the outQr shaped portion by radically poly~erizing the fluorinated monomeric system in the presence of ~t le~st one ~ubstantially unreactive, low molecular w~ight component, the polymerization being initiated at the 0urface of the shaped portion while ~llow~ng the ~h4p~d portion it~elf to simultaneou~ly xpand and dis001ve in the c~ntral fluorinated monomeric 3ystem; the polymer and th~
substantially unreactive component cooperating to form the monolithic molding with a radi~lly gradu~ted refracti~e index.
The proce~ may be used to manufactur~ a variety of shaped articlQs, and in particular, preforms with a graded refractivc index useful in ~anuf~cturing optical fiber~. Preforms fro~ the monolithic transparent thermoplastic molding produced by th~ inventive proce~
may b~ further drawn out into polymer optical fibers with application of ~ ~uitable ~mount of heat. Optical fiber~
with a core Or about 0.1 m~ to about 0.6 mm in diameter and a cladding of about 0.1 to about 10.0 mm in dia~eter are preferred. m e opt~cal fiber~ of the invention have a low attenuation cf~ct, dB/km, pr~erably ranging ~ro~
about 10 to about 400.
~., .:. . - . : . , , .. , ";.. ...
- 2~ 7~3 -i ~ 1120280-311 BRIEF D~SCRIPTI0N OF THE DRAWINGS
Fig. 1 is ~ top view of the ~pp~ratus of Fig.
2;
Fig. 2 is a scAemat$c v~ew ~n 21Qvation of an apparatus u ed for poly~erizing ~ixtures prepared in ac~ordance with th~ pre~ent inv~ntion;
Fig~ 3 i~ ~ ~chematic vi~w in elevation of an app~ratus u~eful for drawing optical fiber ~rom prefor~
prep~red in conn~ction wit~ the ~ppar~tu o~ Fig~ nd 2;
F$g. 4 depicts a graph of re~ractive index distribution of a poly 3FMA gr~ded index (NGRIN") pre~orm rod;
Fig. S show~ a profil~ o~ output pulsQ ~pread through poly 3FMA graded index polymer optical fiber ("GRIN POF"), for ~ fiber length of 40 Gm;
. Fig. 6 is a pro~ile represent~ng tot~l attenuation spectrum (A) MMA based GRIN POF, (B) 3FMA
based GRIN POF;
Fig. 7 is a refractiv¢ index distribution of a poly HFIP2FA GRIN preform rod; ~nd F~g. 8 $s an a~tenuation spectrum of poly HFIP2FA GRIN POF. -~
~:.
DETAILED DESC~IPTION OF THE INYENTIQN :~
The invention is described in detail b~low ln connection with the figures and ~xample~ which ar~
provided for purpo8~ 0~ illustr~tion only. Variouc modificat$ons will be re~dily ~pparent to thos~ of nkill ~ :~
in the art.
I As wi~l furth~r b~ appr~ciated by onQ of ~kill ! in the art, dif~erent re~ractive ~ndice~ between core and cladding in an optical ~iber may be achieved by varying conditions of fabrication, polymerization or bo~h. In the present invention the polymeric shaped articl~6 can c - ~ l 2~ 7~
7 . 1120280-311 be provided with a refractive index gradient by controlling the distribution oP high index component~ in accordance with the decired index gr~dient. In general, fibers produce~ in ~ccordance with the present lnven~ion may have a dif~erence in refractiv~ $ndex, ~nD~ betw~én the core and th~ periphery of ~8 low a~ ~bout 0.0002;
more typically gr~ater than ~bout 0.005.
When ~n $~ 1~8~ than 0.0002, the light is weakly trapped in the cor~. In ~uch a C~8Q, the fiber transmission capacity decrea~e~, since the light rAys ~re likely to be unguided when the optical fiber i8 bent or coiled.
The graded re~ractive index with~n the shaped polymer article~ of the invention i~ rel~ted to the presence of a optically compatibl~ small "gue~t" molecul~
in th2 composition. The gue~t molecule component should not react with the monomer~ o~ the polym~r of which the article is made a~d must be optically compatiblQ compound under the conditions o~ intere~t with the polymer matrix host ~ystem. In general, the ~eatures that the substantially unreactive "guest~ component should possess are: (1) that it hav~ a r~latively high boiling point for purposes of stability, at least about 100C or higher;
(2) that it be highly miscibl~ with the r~active monomeric Ry~t~m 60 that homogeneity is achieved; (3) that it remain optically i~otropic and not cry~tallize under condition~ o~ fabr~cation or use; and (4) that it hava a ~uitable refractiv~ index di~ference from the matrix polymer. Such conditions are referred to hereinaft~r as "optical compatibil$ty~ or a~ ~b~inq optic~lly compatibl~" a~ the ca~ mAy b4. In addition, the mobility of th~ small guest moleculs in th~ poly~r matrix should bQ ~o low that migr~tion does not occur in the temp~rature ranges ~rom about -40C to about 90C.
The substantially unreactiv~ compone~t i8 pre~-r~bly also a halogenated co-pound. m- highly 2~3~7~t refractive nonreactive guest compound additive in the mixture ~hould have a ~olubility difference with the polymer of the matrix from about 5 to about 7 ~cal/cm3)~
or less and a dif~erence o~ refractiv~ ~ndex of a~ least S O.001. Typical concentration~ o~ the substantially unreactive low ~olecular weight compon~nt ar~ from ~bout 1 to about 30 percent ~y weig~t of th- ~ixtur~ and -~:
preferably 1 to 20 percent ~y w~ight o~ the mixture.
one e~bodiment involves polym~riz~g an 10 optically high transmission poly~er o~ low refractive : :~
index in the presence o~ an effective a~ount of a ~ubstantially unreactive low ~olecular weight material ("guest molecule~) having a rel~tively higher re~re~ctive index. The reaction occur~ in a cylindrical reaction 15 vessel, e.g., a glass tube in ~sentlally a on~ step :
process and does not reguir~ the production and u~e of a cladding poly~r tu~e polymerizntion ve~sel. ~he polymerization proces~ i8 preferably of the free radical type (i.e. u.v. or heat initiation) and conveniently takes place in a rot~ry v2~sel upon application o~
~uitable heat or irradiation such a~ furni~hed by ~.V. -: :
light depending on the polymer 8y8t~m.
During polymerization, the low refractive index polymeric matrix initially forms near t~e internal wall 25 of the cylindrical polymerization ve~el and proc~d~ ~
seguentially toward t~e center axis of the v~s~l. A~ -:
the polymerization progresses 80~ 0~ the ~mall high refractive index guest ~olecule~ ~r~ entrapped with$n th~
forming polymer matrix whil~ othera migrate toward the as yet unreacted cor~ o~ th~ ves~l. In tha final product shaped articla the Goncentration of th8 low ~ol~cular weight guest molecule within the polymeric matrix i~ low near the periph~ry, but gradually incr2a#-~ in conc~ntration toward the center axl~. Thi~ concen~ration gradient is a cons-qu~nce o~ the progr~ssion o~ format$on of the polymer matrix. ~he polymeric preform thu3 will exhibit a changing re~ractive index which is highe~t in ~-2~1~ 7~ ~
, the area about the center axis and gradually decreases to th~ lowest index number characteristic ~or the basic homopoly~er matrix near the periphery of She article.
In another embodiment of the invention a graduated index optical fiber may be produced in a preferred embodiment by a two-step procedure. First, a polymeric cladding or tube container whic~ will b~ a p~rt of the final preform ~ produced. The clndding tu~e compri~es a poly~er which has thR desirabl~
characteristics of relatively low re~ractivity and high signal transparency and i8 produced ln a Eultable cylindrical ves~el. Second, th~ core portion, which preferably comprises thæ same polymer a~ the cladding is polymerized within the container ~rom a mixtura o~ a - 15 monomeric sub~tance with the addit~on of an ef~ective amount of a relatively high index low molecular weight guest molQcule. As described ~or the ~ingle ~tsp pr~or~
above, the substantially unreActiv~ additive or doping molecule is distributed in the core portion so that it ~orms a gradient o~ a high re~ractlve indox value nt th~
center axis region whilR decreasing toward th~ periphery.
The cladding polymer, which i6 preferably a halogenated or more pre~erably ~ ~luorinatQd homopolymer, ~u~t be soluble in the core ~iYture o~ th~ basic fluori~ated matrix monomer. The monomRr and the low molecular weight high refractive index guest molecule additive are a~le to dif~use into thQ ~t least partially oxpanding or dissolving matrix on th~ inside surface o~ t~e cladding I polymer portion to for~ a gel-lik~ ~tate. The j 30 polymerization ~ initiated in the ~el-like ~tatu and ¦ proceeds toward~ the center of the ~rticle ~or~ing th~
~mall molecule concentration gradient discu~ad ~ov .
Due to the uniformity and ~olubility of the poly~er the two-3tep or bicomponent polymeriz~t~on re~ults in a monolithic article.
In a preferred embodiment, a polymer matrix i~
~; selected which is produced by fr~ radical ~, :
% ~
polymerization. Radical polymerization i~ initiat~d by the free radicalc pxoduced from a radical polymerizat1on initiator present ~n the ~olution and driv~n by ~-irradiation energy. The energy ~ourc~, R.g., U.V. liqht or I.R. lamp, i~ near the periphQry of the r~action ves~el. Con6equently, the polym~rization procseds from the inside wall~ of the con~ainer toward the center gradually depleting tbe monomer conc~ntration of the remaining ~olution. The r~action væ~el may b~ rotated ~-at a suitable velocity in ord~r to ev~nly r~di~tr~bute the energy input as well ~ th~ monomer~c ~olution. The unreactive high refractiv~ index guest compound concentration increase~ towards thQ center as th~ polymer matrix formation progresse~ toward the center of the reaction ves~el. ~his result~ in a r~fractive ~nd~x gradient from the periphery to th~ c~nt~r ~xi~ of th2 article produced.
In another preferred embodiment o~ the invention, graded index thermopla~tic pr~form~ produc~d by the method~ of the invention are used to ~anufacturo optical ~ibers. A6 i8 well-known to tho~e ~kill~d in the art, the thermoplastic optical fibQr product i~ u~ually formed by heat-elongation or heat-stretching from a 30-called preform of relatively short and thick d~men~ion~
wherein ths 6tructural components ~nd their distribution are s~t. Th~ much narrower tran~verse dimen~ion~ of thR
final fiber product hav a graded r~fractiv~ index similar and related to that of the preform from wh$ch they are produced.
Th~ optical fiber ~a~ mater~al ~u~ta~l~ for the heat-~tretch production of ~ ~ingl--mod~ pla~tic optical fiber ~ay be applied in any o~ ~ever~l geo~tric ~hapes, th~ prsferred baing cylindrical or rod-lik~. For example, a cylindrical preform tran~mitter having ~
refr~ctive ind~x which gradually decreases radially from a relatively high refractive index value at the center axis region (core) to a relatively low refractive index t i 2~ ~17~
-value at the peripheral region is design~ted as a convex lens-acting optical tran~mitter. Thi~ typ~ of light transmitter i~ preferably usRd to manu~acturs a bar-typQ
lens or ~n optical ~ib~r.
S The polymer m~trix of the ~h~ped nrt~clOEis of the invention are comprised of fluorinated polymers.
Fluorinated compound~ are particularly ~uited a~ polymer optical transmit~rs aince their attenuat~on i8 favorably low at wavelength- about 700 nm, i.~. in the visihle spectrum. Noreover, the l$ght transm~s~ion Or fluorinated polymer optic waYeguide~ i~ clearly in?proveid co~pared with the ~tnte of thei art ~nd with optic waveguides containing poly~ers d~riv~d fro~ monomer units which for the most pArt contain hydrogen atom~. The - 15 optic waveiguides manufactured from theso ~luorinated polymers can ~160 be used in the wavelength range of 850 nm in which high performance luminou~ diodes and semico~ductor lasers ~ well as receivers are available 80 that long transmission distance~ o~ light ~ignals are po~sible.
Fluorinated polymer~ u~erul in the pre~ent invention a~ ~he polymer matrix ~ust hav~ a high glass transition point and high light transmittance. Tho~e iluorinated polymers are preferably used which di~pl~y higher transparency than polymethyl methacrylata (FMMA), a poly~er u~ed in the prior art for the ma~uf~cture o~
optical fibers.
~- 211~ 7~i ~
The initial material for the synthesis of the fluorine-containing polymer ~ay be a co~pound o~ ~or~ula I:
CFX-CF-~~-OR
(I) wherein X is ~ hydrog~n atoD or a deuterium ~tom, and R
is a linear, br~nched or cyclic Cl-C~O alkyl group or a ~-C~O aryl group. Th~ hydrogen ~toms o~ R may b~ complat~lyor partially replaced by fluorin~, chlorin~, or bromlna atoms.
The acid co~ponent o~ th~ est~r~, pr~sr~bly consists of 2,3-dirluoroacrylic ~cid or 3-d~ut~ro-2,3--15 difluoroacrylic acid.
The alcohol compon~nt is pre~erably msthanol, a fluorine or chlorine-containing lin~ar or branchQd or alicyclic alcohol with 2 to 10 carbon atom~ or an arom~tic alcohol with 6 to 10 carbon atoms. Preferred are methanol, chlorine and fluorine containing linear or .
branched, or alicyclic alcohol~ with 3 to 10 car~on ~to~
as well as phenols and benzyl alcohol. Especially preferred are methanol, hexaflu~roi~oprop~nol and 2-deuterohex~fluoroisopropanol, ~lkyl ~nd aryl sub6titut~d hexafluoroisopropanols such as per~luoro-2,3-di~thyl-2-butanol, 2-pent~fluorophenylhexa~luoroisopropanol and 2-(p-fluorophenyl)hexafluoroi~opropanol, ~luorin~-and chlorine-containing cyclopentanol~ and cycl~hexanol~ a~
well as 1,4,5,6,7,7-hexachloro- and hexabro~obicyclohept~nol, 1,4,S,6,7-pentachloro- and 1,4,5,6-tetrachlorobicyclohspt~nol, 5,5,6,6-tetraki~(tri~luoro~ethyl)bicycloh~ptanol, 5,6-difluoro-5,6,-(trifluorom~thyl)~icycloheptanol, 5,5,6,6-tetrafluorobicycloheptanol, 1,4,S,S(or 6,6),7,~-35 hexachloro-6~or -5)oxobicyclooctenol or (1,4,5,6,7,7- :
hexachlorobicycloheptenyl)methanol an~ theix deuterat~d ~. ~
:::
2 ~
derivatives, as well as pentafluoro, pentachloro- and pentabromophenol.
Preferably e~ter~ wherein the hydrogen atoms of the alcohol in the acid component are replaced ~
completely as possible by deuterium, fluorine, chlorine or bromine atom~ are used. Preferred e~ters ar~
methanol-d3, 2-deuterohexafluoro~opropanol, trichloroethanolodl, 3-penta~luoroph~nyl-hexa~luroisopropanol, p~rfluoro-2,3-di~ethyl-2-butanol, perfluoro- or perchlorocyclopentanol or cyclohexanol a~
well as l,4,5,6,7,7-hexAc~loro and -hexabro~obi~ycloheptenol-d~, 5,6-difluoro-5,6-bis(trifluoromethyl)bicycloheptanol-d~, 5,5,6,6-tetrakis(trifluoromethyl)bicyclohept~nol-d~, 5,5,6,6,-tetrafluorobicycloheptanol-d", 1,4,5,5~or 6,6),7,8-hsxachloro-6~0r-5)0~0bicyclooct~nol-d3, or (1,4,S,6,7,7-hexachlorobicyclohepteny~)~ethanol-d5, pentafluorophenol or pentachlorophenol.
It is preferred th~t the hydrogen atom in the acid component, and possibly the hydrogen atom or atom~
in the alcohol component be replaced by on~ or ~or~
deuterium or fluorine atoms since the hydrogen atom~ may i~pair the transparency of the polymers in th~ u~eful vi~ibl~ and in the near-infrared region of th-electromagnetic ~pectr~m.
The 2,3-difluoroacrylic acid ester~ according to For~ula I may ~e ~ynthesiz~d by e~tarirication of 2,3- -dichloro-2,3-difluoropropionic ~cid or a corresponding acid h~lide w$th an alcohol of the formula R-OH, wherQ R
ha~ the meaning given in formula I, and sub~eguænt dehalogenation with zinc. Thq corresponding 3-deutero-2,3-di~luoroacrylic ~cid ester~ 3r6 obtain~d by e~teri~ication o~ the 3-deutero-2,3-difluoroacrylic ~cid or its acid halide w$th an alcohol a~ de~cribed abov~.
In a preferred embodi~ent the poly~r matrix of the shaped articles of the invention may be produced fro~
units derived from one or more e3t~rs o~ formula II~
~X',, 2 1 ~ ~ 7 t~
CYY'~CX-Q OR
(II) where X denote~ a hydrogen or a deuterium atom, C~-C~
alkyl, prefer~bly r~thyl, c.r ~ fluorine atom; Y d~notes a hydrogen or a deut~riu~ atom; Y' denot~ a hydrog-n or a deuterium ~tom; ~nd R is ~ lin~r, branch~d or cyclic C1-Clo ~lkyl group. Th~ hydrog~n atom6 in X, whQn X i~ Cl-C~
alkyl, or ~ may be totally or psrti~lly r~pl~c~d by fluorine atoms.
Suit~ble ~luorinated polymers ar- polym~ric 2- :~
fluoroacrylic acid ~ster~, especi~lly e~ter~ o~ aliphatic alcohol~. Tha~e polymeric material~ ~ay contain deuteriu~ atom~ both in the ~lcohol ~nd ~lso in the ~
po~ition of th~ 2-fluoro~crylic aci~ compon-nt (~ EP
128517). Thes~ polymer~ have indice~ Or r-fraction between 1.45 and 1.60 and glas~ tran~it~on point~ ~tw~Qn loO~ and 200C and thu~ may ~erv~ ~ the polym~r m~trix material for optic wa~e~uides or optic ~ib~rs. Polymeric 2-fluoroacrylie acid esters of ~rominR, chlorin~, fluorine or deuteriu~ containing alcohol~ m~y also b~ - -usQd. ~:
Especially preferred are polymer~ obtain~d essentially from 2-~luoro~crylic acid methyl e~ter3, ~ro~
2-fluoro- and 2,3-difluoroacrylie ~c~d ~ster~
~ethacrylic ~c~d ~st~rs and acrylic acid ~ster~, o~
hexafluoroi~opropanol and 2-d-uterohexa~luoroi~opropanol, 30 alkyl and aryl ~ubstituted h~xa~luoroisoprop~nol~ ~uch ~ ;
per~luoro-2,3-dimethyl-2-butanol,2~
penta~luorophenylh~xa~luoroi~opropanol ~nd 2-(p- -fluorophenyl)h-xafluoroisopropanol, fluor~nQ- and , chlorine-cont~ining cyclopentanol~ and cycloh~xanol~ a~
f 35 well a~ 1,4,5,6,7,7-hexac~loro- and f hexAbromobicyclohept~nol, 1,4,5,6,7-pentachloro- nnd 7 1,4,5,6-tetrachlorobicycloheptenol, 5,5,6,6~
.
:, .. ,. . - : . ,, .. :. ., . . . - ~
2~ ~ ~7'; ~
_~.
lS 1120280-311 totr~kis(tri~luoro~ thyl)bicy~loheptanol, 5,6-dirluoro-5,6-(trifluoromethyl)bicycloh ptanol, 5,S,6,6-te~r~rluorobicycloh~ptanol, 1,4,5,5(or 6,6),7,8-hDYaohloro-6(0r -S)oxoblcyclooct nol or (1,4,5,607,~-S hox~ch~orobicycloh-pt-nyl) tb~nol ~nd th~ir d~ut~rat~d d-rivativea, as ~11 a~ p-nta~luoro, p~nt~chloro- and pen~abronoph-nol.
Pr~r~bly ~t~r~ wh r-in th hydrog n ~to~ o~
th~ ~lco~ol ~n th~ ~ia oo~pon nt ar~ r-plac~d a~
co~plet~ly as pc#sibl~ ~y d~utQrlu~, ~luor~no, chlor~n~, or bro~in~ ar~ uJ-d. Prer-rr~d e~ora ~ro ~o ~ ol-d~ 2-d~utsroh~xaSluoroi~opropanol, tr~e~lorooth~nol-a2, 3-pont~luoroph~y~h~xa~l~oroi~opropRnol, p r~luoro-2,3-~mot~yl-2-butanol, p~r~luoro- or perchlorocyelop~ntanol or eyelo~exanol ~ well ~5 1, 4,5,S,7,7-hu~a~hloro and -hex~bro~obieyelo~pt-nol ~ , 5,6-di~luoro-S,6-bi~(tri~luoro~thyl)bleyeloh pt~nol-d", 5,5,6,~-t~tr~ki~(tr~luo~o~-thyl)bley~loh~pt~nol-dll, 5,S,6,6-t~txa~luorobieyelo~qptanol-dl" 1,4,5,5~or C,6),7,~-h-Y~ehloro-6(or -5)oxo~1eyelooct~nol-d~, or ~ ,5,~,7,7-h-xaehlorobleyelo~ nyl)~o~hanol-~, pon~a~luorophYnol or p-ntaehlorop~nol.
P~ors~d ~olys~rs ~or ~roducing GRIN p~e~o~3s un~ul ~or th~ ~nuSactu~ o~ op~ical ~ib~r~ ar-poly(trifluoro thyl-2 fluoroacryl~t~ poly 3FFA~);
poly-~tri~luoroethyl ~thac~ylat~ poly 3FMa~); ~nd poly-~2-fluors~c2yl~c, hexa~luoroi~opropy~ ~c~d) (~poly HFlP2FAU). 0~ th--J--polyz~--, poly 3FP~ ~ t v~ry ~oluble ln it- ~ono~r rrA ~nd i- th r-rOr- not ~ -rul ln the two-~Sep polynQ~i8at~on proaes~ o~ the ~nv~ntion u~ing t~ ~ir~t ~top preparation o~ tb0 ~ladding tubQ.
P~ly-3F~A ~nd ~oly ~FIP2~A ~r- ~olubl- in th ~r ~cno~er~
and thu~ u~ful in kDtb n thods o~ th~ in~Qnt~on. The preferr~d 2-~luoroacrylic acid ~onomer i~ 2-~l~o~o~crylic acid h-x~luoroi~opropy~l t~r (~F~n FA~).
Sub~tantially unr~acti~ fl~al~ gu~t ~olecul-~ar~ understood to include low ~ol~cula~ wsig~t coypoun~s ~.,r''' ' '" ' '' '' ' '~' ' "' - " ~' , '' ':
21~ l7~1 w~ich do not polymerize with the basic mono~ers or polymeric ~atrix. It i~ presumed that t~e ~mall molecules do not react radically within the condition parameters prevailing during the gel formation and post polymerizati~n treatment. Typically, the low ~olecular weight guest compounds are selected from certain high refraction index ~liphatic~l; or alkylaromatics, which may be optionally substitute~ with, ~.g., ~alogen atom~ and prQfer~bly fluorinQ atom~. The gu~t molQcul~ o~ cour~e must be selected so that it i~ optically compatible with the particular polymer ~ystem o~ the ~hap~d article.
Suitable ~mall molecule~ may ~e selectQd from, but not limited to, the group o~ dibutyl phth~late, benzyl benzoate, butyl phenyl phthalate, benzyl-n-butylphthalate, 1-methoxyphenyl-1 phenyl ethane, 3-phenyl-1-prop~nol, bromo~enzenQ, m-dichlorob~nzene, 1,2-dibro~oethane, o-dichlorobenzene, bis(1,1,1,3,3,3 ~-hexafluoroisopropyl)terephthalate, and other halogenated or, preferably, ~luorinated aromatic~.
In a preferred embodiment of the invention the small guest molocule is a molecule of the formula III:
O
~ ont ;
l (III) OR ~ .
O
wherein Rf is C~-C~0 ~l~yl, C~-C,0 aryl or a parti~lly or fully halogenated C~-C,0 alkyl or ~-C,0 aryl group.
~ he production and propertie~ of the poly-(2-fluoroacrylic acid fluoroalkyl ester~) are known in the art (~ee EP 128516). Polymerization of ~ono~er~ i~
conducted in ~olution or suspension by radical initiation in the presence of a chain-transfer agent at a temperature approximately between 0 and 100C.
.~ ; 2 1 ~
The polymer matrix compound can option~lly be produced by free radical poly~erization in solution in the presence of ~n initiator. Suit~ble radically ~cting initiators u~eYul in uch polymerization~ ar~ azo compounds ~uch ~ azo-bi~-$~o~utyron$trile, azo-~e-(cyclohexylcarbonitril~), azo-bi~-(t-octane), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile ~nd organic peroxide~ ~uch ~ t-butyl poroxide, t-butyl peroctanoate, t-butyl peroxyi~opropylcarbonate, t-butyl hydropero~ide, t-butyl peroxyisobutyrate, and dicumyl peroxida. The guantity of the initiator lia~ $n th~ range ~rom 0.001 to 3.0 moles, pre~erably 0.036 to 1.0 mol~ per 100 moles o~
mono~er.
The polymerization may also take place in the presence of a chain tran~fer medium (regulator or agQnt)_-Especially suitable ~or this ar~ ~ercaptans such as n- or t-butyl mercaptan, propyl mercaptan, phenyl mercaptan, t-hexyl mercaptan and butylen~-1,4-dithiol a~ well a~
esters of mercaptoacetic acid, ~.g. mQthyl-mercaptoacetate, ethylene glycol-bi~(mercaptoacetate).
The polymarization temperaturs ~hould ~Q in the range of 20 to 180-C, pre~erably 40 to 160C, ~nd mor~
preferably 60 to 140C.
It i8 racommended that the mixture be degassed before polymerization. For thi5 purpos~ th~ reaction mixture of monom~r, unreactive ~mall ~olecul~, one or more initiator~ and regulator~ ir~t cooled in a reactor to a temperature o~ at lQa~t -80~C, th~n the reactor is ev~cuated and warmed in the clo~ed ~tat~ to a ~emperatur~ of 0 to 25~C. ~hi~ proce~ is pre~rably repeated eeveral times. Altarnati~ly, th~ reaction mixture may hav- ~ stream o~ hydrogen, heliu~, ~rgon or nitrogen gas which ie pas~d down to th~ ~loor o~ th~
reactor through ~n i~m~r~ed ga~ pipe for ~ period o~ ~ 1 to 60 min, pref~rably 5 to 30 min.
2~1~ 7~
lB 1120280-311 FABRICATION METHODS
One general methodology use~ul to make preforms and optical ~iber in accordanc~ wi~h th~ pre~cnt invent~on i~ de~crib~d in U.S. Pat~nt No. 4,521,351.
Referring to F~g~ nd 2, a ~ono~eric ~ix*ure of the ~no-2r and ~all gue~t mol-cul6 ~ fill~d ~n glas~ tube 4 having a closed end and an in~de di~met~r of about 3 ~ to abo~t 10 J~. A tubular ultrnv~olet lamp 1 is located centrally ~n t~e ~pparatu~, and a cylindrieal light-shielding plate 2 i~ ~ecured to each o~
the upper and lower section~ of the l~p 1 80 tha~ the ~ 15 mixture in th~ gla~s tube 4 i6 $rradiated only by ultraviolet light relea~ed ~ro~ th~ centr~l portion o~ `
the tu~lar la~p. ~ collar-lik~ auxiliary light-~hielding plate 11 i~ provided ~o that the light from the la~p 1 i6 releas~d only in~o ~ pace between the light shielding plate~ 2 ~for ~xa~ple~ 70 mm). The i~ten~ity of ultraviolet light i~ ~onitored by a ~ilicon photocell ~ :
3. The intensity Or the ultr~violet ligh~ i6 pre~erably maintained con~tant during polymerizat~on. A plurality of glass tubes 4 filled with the monomeric ~ixture are ~ounted on a ~upport ~e~ber 5 at a predeter~ined dii3tance, for ~xAmplQ 10 cm, from t~e ultraviolst la~p 1, and rotated at ~ isp~ed o~, ~or xampl~, 40 rpm by ~ ~otor 6. Initially, thQ ultraviolet la~p, for cxampl~ 00 W
lamp, ii~ placed ~t ~ position lower th~n the lower ~nds of the gla~ tubei~ 4, ~nd ultraviol~t l~ght i~ irr~diat~d onto thc glass tub~s 4 whil~ thc l~mp 1 iB moved upwardly by a ~otor 7 ~t a pr~d~ter~ined rat~ o~, for ~xampl~, 0.3 to 3.0 ~/min. Air 2t a fix~d temperatur~ Qn~ in~o the apparatu6 by æ ~n 9 ~rom ~n ~nl~t 8, ~nd di~charged ~ro~ a discharg~ op~ning 10. ~he temperature o~ the inside of th~ apparatu3 rise~ duQ to the generation o~
heat from the lamp 1, but beco~e~ constant nt f l 2~ 7l~
temperature 60me degrees higher than the temperature o~
the air current.
Photopolymerization by a ~ree r~dic~l mechanism 6tart~ at the outside portions Or the bottoms oS ~he 5 glass tube~ 4 which re ~irst expo~ed to ultraviol~t radiation. Volume shrinXag~ ~Ay occur du~ to polymerization. But ~inc~ unr~ac~d mono~eric ~ixture is fed ~rom that part ~n th~ uppar ~ction o~ ~ach o~ th~
glass tube~ wh$ch has not yet und~rgon- ultraviol~t 10 irr~diation, no space ls formod inside th~ polymor matrix.
With ~he ~ovement of the lamp 1, polymerization proceeds gradually upward until all of the monomer$c 8 miYture in each glass tube 4 i8 601idifiRd. After the ;~
15 lapse of a predetermined per$od o~ time from the start of irradiation, for ex~mple a~out 10 hour~, th~ ultraviolet irradiation iB stoppQd, and th~ gla~ tubes 4 ars removsd from the apparatus. Th~ gla~E tube~ ~ay then b~ heated to a temperatur~ ~ufficient to polymeri2~ the remaining 20 mono~ers as completely as pos~ibl2. ~hi~ temperature dependent on the type of poly~er ~y~tem being u~ed, an~
should preferably be a te~peratur~ above that o~ the interior of the poly~erization apparatu~.
Aft~r polymeriz~tion i5 co~pleted, the gla~s 25 tubes are crushed, and the prefor~ rod~ are taken out.
Each of th~ rodQ show a fixed re~ractiv~ index distribution exc~pt at the ~nd portlnn~. Light-converging fib~r~ can b~ obtained ~y h~ating ~nd stretching e~ch of the re~ulting rod~ (light-tran~mi~ting 30 elements~. It i~ recom~ended that prior to heating and strQtChing 0~ thQ rods, the rods ar~ left to ~tand under a reduced pre~uræ of 10~ to 101 ~m~g at 50-C for 3 to 4 days in order to remove trace~ o~ volatil~ substances contained in the rod~. The post tr~at~ent may al~o apply 35 a heat-6hrinXing tube whereby bubble for~ation i~
suppressed.
- ' 2~ fi~
Fiy. 3 ~hows a heat-drawing apparatu~ ~howing the principle on whic~ the rods are ~e~t-drawn into optical fiber~. Typic~lly ~ rod o~ 1~88 th~n half a meter in length i8 mounted on a ~upport ~ember 22, and S then allowed to desc~nd vQry ~lowly at a velocity V~
(mm/~ec), pas6ed betwaen h~aters 23 ~t ~ *ix~
temperature Td, and pulled ~nd stretched ~t ~ groat~r velocity o~ V2 ~m/~ec by a driv~ roll 24 h~low.
The ~ollowing ~xa~pl~ p~rtain to sdvantageou~
use of certa~n ~luorinated homopolymQrs in ~ccordancQ
with the present invention where$n th~ h~gh refraction :
index monomer or small molecules ~re di~tri~ut~d a~
refractive components in a gradient ~rom th- core to the cladding portion of the optical fiber.
~ , Monomeric mixture for ~roduct~on o~ P3FMA tub~:
Poly(tri~luoroethyl methacryl~t~) graduatod index plastic optical ~iber (P3FMA GRIN POF) was produced as follows:
(a~ Preparation o~ ~ube/claddina.
A monomer mixture co~pri~ing 3FMA gl,l,1-trifluorosthyl methacrylate) monomer with the addition of ~enzoyl peroxide (BPO), 0.5 wt~ (weight percent), as an initiator; n-lauryl mercaptan 0~1 wtt a~ a chain trans~Qr ag~nt wa~ pr~par~d. Th~ mixtur~ wa~ plac~d in a gla~
tube with a 20 ~m inner diamater. A~t~r being ~al~d on oppo6it~ end~, thQ gla~s tuba wa~ placed ~or ~er~al polymerization of the monomer~c DixtUr~ horizont~lly in furnace at 70C.
The tube was rotat~d a~out ~ts cent-r ~xic at 2000 rpm ~or a polym~rization tima of about 20 h. ~f~r polymerization the outer glas~ tube was broken and removed. The outer ~nd inner diamet~r o~ the P3FNh tub~
product or cladding wa~ 20 mm ~nd 1~ m~, re~p~ctively.
- , - i .. . . , ., , .. ,-, . ~ .
- i 21~17~; ~
(h) Preparation of GRXN_~re~or~ rod:
A monomeric mixture COmpriBing 3FMA monomer ~nd the 6ubstantially unreactive small molecule, Dibutyl phthalate (DBP), in ~ 3FMA/DBP w~ight rat~o o~ 5/1; with S the addition of 0.5 wt%~ Bis tt-butylp~roxy)3,5,5-trimethylcyclohexan~ (PH3M) ~ initiator; And 0.1 wt% n- -lauryl mercaptan as cha~n transf~r ag~nt W~8 prep~r~d.
ThQ P3FMA tubs producsd ~n ~tep (a) was filled with the monomer ~xturQ and ~al~d, thQn placQd horizontally in a ~urnaco ~t 95-C. for thermal polymerization while rotating at a~out 30 rpm. ~h-polymerization time was about 24 h.
As a post-tr~atment, the preform rod was heat- -treated at 100C under about 0.2 mm ~g atmosphers for 24 h. The resulting polymer had a content o~ residual unreacted monomer of 0.5 wt.% or less. The eladding and core portions were thus integrated into a monolith.
(c) Preparation of GRI~ F~F:
After th- GRIN preform monolithic rod wa~ cut at opposite end~, the pref~r~ rod was heat-dr~wn at 200C. to form an optical fiber of ~bout 0.6 mm diameter.
A refractive index distribution of the preform (shown in Fig. 4) was measur~d by the int~rfero~Qtric technique.
(d) Optical P~o~ertv o$ the P3FMA GRIN POF
The bandwidth of the G~IN POF wa~ mea~ur~d ao follow~
A pulse of 10 M~z ~rom a lAser diode (InGaAlP;
wavelength ~670 n~) was introduced (N.A.-0.5) ~nto ~ 40~
long sampl~ fib~r. The output puls~ w~ d~tected by ~-6ampling hend (mod~l OOS-Ol, Hamamat~u Pbotonic~ Co.).
The result i~ 3hown ln FigO 5. Th~ bandwidth 3S was estimated from the 3d8 level in impulee respan~e ~u~ct~o~
'` . ~ 2~ ~17~
:
The bandwidth of the 40 m ~iber length o~ ~3FMA
GRIN POF with the FWHM (~Pull width at half maximum~) of the input pulse at 80.5 ps and output at ~7.5 p~. was 632 - MHz/k~. ' A total attenuation pectrum of th~ GRIN POF ~ 8 shown in Fig. 6.
S~NP~ 2.
A GRIN POF utilizing a ~luorinated monomer ba~e prepared as described in thi~ example at a diameter of 0.6mm exhibited the following op~ical characteriza~.'.ion.
The attenuation of transmis~ion at 780 nm w~velenqth w~
found to be about 200 dB/km and apparently much low~r ~han that of comparatively preparsd ~ethyl methacrylate (MMA)-base GRIN POF (700dB/k~
~ he cladding material was compo~ed of the pure homopolymer, poly~FIP2FA). The advantnge o~ ~uch a compo6ition i~ that ther~ i3 no need to U8- ~ highly perfluorinated cladding ~aterial wlth the concomitant disadvantag~ of low optical clarity and crystallinity.
(a) Preparation of HFIP2F~ tube eladding:
A mo~omer mixtur~ compr~ing HFIP2FA monomer, 0.06 wt.~ of Benzoyl peroxide ~BPO) a~ ~n initiator and 25 0.10 wt.% o~ n-lauryl mercaptan a~ a chain transfer agent -~ ~
was prepared. The mixture wa~ placed in a gla~ tuhe -.
with a lOmm inner di~met~r, ~ tu~e cladding wa~ produced .
by th- method of ExamplQ l(a), abov~.
The mixture was placed in a gla36 tubQ with 10 mm diameter, bo~h end~ wera ~ealed ~nd tha gla~ ~ub~
wa~ plac~d hor~zontally in ~ furn~c~ ~ in the ~ethod oP
Exa~pia l(a). The tub- was rotated about it~ axia at -:
1000 rpm at 70DC ~or about ~0 h. Th~ out~r and ~nn~r ~ -diameters o~ the resulting HFIP2FA polymer cladding tu~e were approximately 10 m~ and 6 mm, re~pectiv~ly.
2~7fi~
(b) ~reparation_o~ ÇRI~ ~xefor~ Rod.
A monomer mixture eomprising HFIP2FA monomer with Dibutyl phthalate (DBP) ac th~ unreactive ~mall ~olecule component in ~ ~FIP2FA/D~P weight r~t~o o~ 10/1, with O.2S wt% t-Butyl peroxy ~sopropylcarbonatQ (~PPC) (fro~ Nippon Oil And Fats Co.) a~ in~tiator, and 0.10 wt.% n-lauryl ~erc~pt~n as the chain ~ransfer ~gent wa~
prepar~d. The polymerlzation temperatur~ of the ~ixture iR 95C.
~he tu~e cladding wac pla~ed within a hoat shrink tube (FEP-090 from Plon Rogyo Co.), ~illed with ~ono~er mixtur~ sealed and pl~ced in ~ furnace. A~ter A
20 h polymerization at the mixture polymerization temperature with rotat~on, each preform rod with heat shrlnk tube was heat treated at 110C under normal pressure for one day followed by a heat treatment without - the heat-shrink tube at 1l0CC for 20 h under ~ pressure of 0.2 ~ ~g.
(c) PreDaraticn of GRIN POF~
The GRIN POF wa3 obta~ned by the heat drawing of the above GRIN preform rod~ at 200-220C. The optical :~
fiber obtained w~ 0.6 mm ln diameter ~nd 50 m long.
Following polymerization of the tube claddin~
25 the tube had a ~lightly yellow coloration rend~ring it --~
less desirabl~ for ~anufacture of optical fib . ~ub~
cladding produc~d under Example 3 b¢low wa~ transpar~nt and usQd to produce optical ribere with tha low~t ~ -attenuation. :~
pXAMP~J 3 . To reduca the for~ation Or color, it ~a ~ound that the i~itiator azobi~i~obutylonitrile (AIBN~ could be substituted for benzoyl peroxid~ in ~h~ procsdure of ~.
Exa~ple 2 and the polymerization temperature reduced.
Specific for~ulations were~
21~ ~.7~
(a) Tube Claddin~:
~ono~er: HFIP2FA, Initiator: 0.05 wt% AIBN
Chain ~ran~fer agent: 0.15% n-lauryl m~rcaptan;
(b) Prep~ration of Preform Rod:
~onomer: HF~P2FA, U~reactivQ Component: dibutyl p~talat~ (DBP), Feed ratio of 10/1, HFIP2FA/D8P, Initiator: AIBN 0.07 wt~
Claim transfer agent: 0.10% n-lauryl merc~ptan Polymerization Temperature: 65C.
O~tical pro~erties:
The opt~cal fiber of Exa~ple 3 exhibited a lower attenu~tion than that o~ Ex~mpl~ 2. A r~ractivQ
index distribution of the preform of Exampl~ 3 wa~
measured by the trAnsv~r~e interferom~tric t~chnique.
The total attenuation spectrum of the GRIN POF of Example 3 is shown in Fig. 8. The ~inimum attenuation of transmission i~ only 209.1 dB/~m ~t 780nm wavelength measured incidentally with ~ commercially available Laser Diode. ~n contrast, the attenu~tion number~ of P~MA-~ased and 3FMA-based GRIN POF at 780 nm are about 700 dB/km and 400 d~/km, respectively.
XAMP~ ~
Following the procedure of ~xample 2 ~ GRIN ~OF
fiber ~ay be prepar~d using ~ ~onomer of the ~tructural formul~ IV:
C
Il - ~r5 for both tube cladding and cor~ of the preform.
2~7~1 , ~ , .
~AMP~_S
Following the procedure o~ Example 2 a GRIN POF
fiber may be prepared using a monomer of the structural formula V: F
s a-~=c Il--~all-cc for both tube cladd$ng ~nd cor~ o~ the preform.
Poly~erization is ~nitiated ~t a ~urface o~ the polymerization ve~sel ~nd as polymerization progresses, the 6ubstantially unr~active compound di~fuses within the article toward~ the cent~r or cor~ go that ~ re~ractiv~
index gradient in a specific direction i~ obtained. The refractive index of the shap~d nrticles ~f the present invention is continuou~ly and radially vari~d from the center of the shaped article. The preferred difference in re~ractive index between the core and periphery of the article is ~t least 0.001.
The ~haped article may be rormed by u~ing a container tube a~ the polymQriz~tion reactor to produce the monolithic article. Alternatively the tube reactor is first used to produce ~ cladding polymer re~ction tube, which cladding in turn serves a~ the polymerization vessel and beco~e~ a part o~ the monolithic article upon completion of the reaction. In 6uch a process, the polymer of the cladding tube must expand as a gel in the presence o~ the core ~atrix monomer and must be ~t laa~t partially solubl~ therein. A$ the inner polymer wall of the polymer cont~iner 6~ells and partially dissolv~ in the monom~ric csre ~ixture plac~d in6ide the polym~r container, the corQ monomer ~imultnneously undergo~
succ~siva polymerization. The polymeri~ation occurs morQ rapidly in th~ gsl stat~ Or th~ inn~r wall o~ thQ
contain6r. As the poly~erization proc~ds, the unreactive guest molecule ccmponent migr~te~ toward th~
center of the article. After the polymerization ha~ b~en completed the concentration gradient of the unr~active ~ -high refractive index component i~ continuou~ly incr~asing ~rom the periphery~ to the core area of the 2 ,1. ~ & 1 polymeric ~onolithic body. The refractive index profile of the article is also pr~sent a3 a gr~dient.
Articles ~uch as an optically tran~parent poly~eric preform rod having a gradient refrective index produced by thi6 method are suitabl~ for hot-strotching into optical wave guide~ or fiber e~bodiments which retain a proportion~te di~tribution of refractiv~
ind:ces.
The pre~ent inv~ntion al~o concern~ A process for the fabrication of monolithic tran~par~nt th~rmo-plastic moldings or shaped Article~ comprising tbe step~
of (a) forming an outer shaped portion, ~uch as ~ '.ube of cylindrical dimensions, by radically polymeriz~ng a fluorinated monomeric system in a 6uitable vessel;
lS (b) forming a central portion within the outQr shaped portion by radically poly~erizing the fluorinated monomeric system in the presence of ~t le~st one ~ubstantially unreactive, low molecular w~ight component, the polymerization being initiated at the 0urface of the shaped portion while ~llow~ng the ~h4p~d portion it~elf to simultaneou~ly xpand and dis001ve in the c~ntral fluorinated monomeric 3ystem; the polymer and th~
substantially unreactive component cooperating to form the monolithic molding with a radi~lly gradu~ted refracti~e index.
The proce~ may be used to manufactur~ a variety of shaped articlQs, and in particular, preforms with a graded refractivc index useful in ~anuf~cturing optical fiber~. Preforms fro~ the monolithic transparent thermoplastic molding produced by th~ inventive proce~
may b~ further drawn out into polymer optical fibers with application of ~ ~uitable ~mount of heat. Optical fiber~
with a core Or about 0.1 m~ to about 0.6 mm in diameter and a cladding of about 0.1 to about 10.0 mm in dia~eter are preferred. m e opt~cal fiber~ of the invention have a low attenuation cf~ct, dB/km, pr~erably ranging ~ro~
about 10 to about 400.
~., .:. . - . : . , , .. , ";.. ...
- 2~ 7~3 -i ~ 1120280-311 BRIEF D~SCRIPTI0N OF THE DRAWINGS
Fig. 1 is ~ top view of the ~pp~ratus of Fig.
2;
Fig. 2 is a scAemat$c v~ew ~n 21Qvation of an apparatus u ed for poly~erizing ~ixtures prepared in ac~ordance with th~ pre~ent inv~ntion;
Fig~ 3 i~ ~ ~chematic vi~w in elevation of an app~ratus u~eful for drawing optical fiber ~rom prefor~
prep~red in conn~ction wit~ the ~ppar~tu o~ Fig~ nd 2;
F$g. 4 depicts a graph of re~ractive index distribution of a poly 3FMA gr~ded index (NGRIN") pre~orm rod;
Fig. S show~ a profil~ o~ output pulsQ ~pread through poly 3FMA graded index polymer optical fiber ("GRIN POF"), for ~ fiber length of 40 Gm;
. Fig. 6 is a pro~ile represent~ng tot~l attenuation spectrum (A) MMA based GRIN POF, (B) 3FMA
based GRIN POF;
Fig. 7 is a refractiv¢ index distribution of a poly HFIP2FA GRIN preform rod; ~nd F~g. 8 $s an a~tenuation spectrum of poly HFIP2FA GRIN POF. -~
~:.
DETAILED DESC~IPTION OF THE INYENTIQN :~
The invention is described in detail b~low ln connection with the figures and ~xample~ which ar~
provided for purpo8~ 0~ illustr~tion only. Variouc modificat$ons will be re~dily ~pparent to thos~ of nkill ~ :~
in the art.
I As wi~l furth~r b~ appr~ciated by onQ of ~kill ! in the art, dif~erent re~ractive ~ndice~ between core and cladding in an optical ~iber may be achieved by varying conditions of fabrication, polymerization or bo~h. In the present invention the polymeric shaped articl~6 can c - ~ l 2~ 7~
7 . 1120280-311 be provided with a refractive index gradient by controlling the distribution oP high index component~ in accordance with the decired index gr~dient. In general, fibers produce~ in ~ccordance with the present lnven~ion may have a dif~erence in refractiv~ $ndex, ~nD~ betw~én the core and th~ periphery of ~8 low a~ ~bout 0.0002;
more typically gr~ater than ~bout 0.005.
When ~n $~ 1~8~ than 0.0002, the light is weakly trapped in the cor~. In ~uch a C~8Q, the fiber transmission capacity decrea~e~, since the light rAys ~re likely to be unguided when the optical fiber i8 bent or coiled.
The graded re~ractive index with~n the shaped polymer article~ of the invention i~ rel~ted to the presence of a optically compatibl~ small "gue~t" molecul~
in th2 composition. The gue~t molecule component should not react with the monomer~ o~ the polym~r of which the article is made a~d must be optically compatiblQ compound under the conditions o~ intere~t with the polymer matrix host ~ystem. In general, the ~eatures that the substantially unreactive "guest~ component should possess are: (1) that it hav~ a r~latively high boiling point for purposes of stability, at least about 100C or higher;
(2) that it be highly miscibl~ with the r~active monomeric Ry~t~m 60 that homogeneity is achieved; (3) that it remain optically i~otropic and not cry~tallize under condition~ o~ fabr~cation or use; and (4) that it hava a ~uitable refractiv~ index di~ference from the matrix polymer. Such conditions are referred to hereinaft~r as "optical compatibil$ty~ or a~ ~b~inq optic~lly compatibl~" a~ the ca~ mAy b4. In addition, the mobility of th~ small guest moleculs in th~ poly~r matrix should bQ ~o low that migr~tion does not occur in the temp~rature ranges ~rom about -40C to about 90C.
The substantially unreactiv~ compone~t i8 pre~-r~bly also a halogenated co-pound. m- highly 2~3~7~t refractive nonreactive guest compound additive in the mixture ~hould have a ~olubility difference with the polymer of the matrix from about 5 to about 7 ~cal/cm3)~
or less and a dif~erence o~ refractiv~ ~ndex of a~ least S O.001. Typical concentration~ o~ the substantially unreactive low ~olecular weight compon~nt ar~ from ~bout 1 to about 30 percent ~y weig~t of th- ~ixtur~ and -~:
preferably 1 to 20 percent ~y w~ight o~ the mixture.
one e~bodiment involves polym~riz~g an 10 optically high transmission poly~er o~ low refractive : :~
index in the presence o~ an effective a~ount of a ~ubstantially unreactive low ~olecular weight material ("guest molecule~) having a rel~tively higher re~re~ctive index. The reaction occur~ in a cylindrical reaction 15 vessel, e.g., a glass tube in ~sentlally a on~ step :
process and does not reguir~ the production and u~e of a cladding poly~r tu~e polymerizntion ve~sel. ~he polymerization proces~ i8 preferably of the free radical type (i.e. u.v. or heat initiation) and conveniently takes place in a rot~ry v2~sel upon application o~
~uitable heat or irradiation such a~ furni~hed by ~.V. -: :
light depending on the polymer 8y8t~m.
During polymerization, the low refractive index polymeric matrix initially forms near t~e internal wall 25 of the cylindrical polymerization ve~el and proc~d~ ~
seguentially toward t~e center axis of the v~s~l. A~ -:
the polymerization progresses 80~ 0~ the ~mall high refractive index guest ~olecule~ ~r~ entrapped with$n th~
forming polymer matrix whil~ othera migrate toward the as yet unreacted cor~ o~ th~ ves~l. In tha final product shaped articla the Goncentration of th8 low ~ol~cular weight guest molecule within the polymeric matrix i~ low near the periph~ry, but gradually incr2a#-~ in conc~ntration toward the center axl~. Thi~ concen~ration gradient is a cons-qu~nce o~ the progr~ssion o~ format$on of the polymer matrix. ~he polymeric preform thu3 will exhibit a changing re~ractive index which is highe~t in ~-2~1~ 7~ ~
, the area about the center axis and gradually decreases to th~ lowest index number characteristic ~or the basic homopoly~er matrix near the periphery of She article.
In another embodiment of the invention a graduated index optical fiber may be produced in a preferred embodiment by a two-step procedure. First, a polymeric cladding or tube container whic~ will b~ a p~rt of the final preform ~ produced. The clndding tu~e compri~es a poly~er which has thR desirabl~
characteristics of relatively low re~ractivity and high signal transparency and i8 produced ln a Eultable cylindrical ves~el. Second, th~ core portion, which preferably comprises thæ same polymer a~ the cladding is polymerized within the container ~rom a mixtura o~ a - 15 monomeric sub~tance with the addit~on of an ef~ective amount of a relatively high index low molecular weight guest molQcule. As described ~or the ~ingle ~tsp pr~or~
above, the substantially unreActiv~ additive or doping molecule is distributed in the core portion so that it ~orms a gradient o~ a high re~ractlve indox value nt th~
center axis region whilR decreasing toward th~ periphery.
The cladding polymer, which i6 preferably a halogenated or more pre~erably ~ ~luorinatQd homopolymer, ~u~t be soluble in the core ~iYture o~ th~ basic fluori~ated matrix monomer. The monomRr and the low molecular weight high refractive index guest molecule additive are a~le to dif~use into thQ ~t least partially oxpanding or dissolving matrix on th~ inside surface o~ t~e cladding I polymer portion to for~ a gel-lik~ ~tate. The j 30 polymerization ~ initiated in the ~el-like ~tatu and ¦ proceeds toward~ the center of the ~rticle ~or~ing th~
~mall molecule concentration gradient discu~ad ~ov .
Due to the uniformity and ~olubility of the poly~er the two-3tep or bicomponent polymeriz~t~on re~ults in a monolithic article.
In a preferred embodiment, a polymer matrix i~
~; selected which is produced by fr~ radical ~, :
% ~
polymerization. Radical polymerization i~ initiat~d by the free radicalc pxoduced from a radical polymerizat1on initiator present ~n the ~olution and driv~n by ~-irradiation energy. The energy ~ourc~, R.g., U.V. liqht or I.R. lamp, i~ near the periphQry of the r~action ves~el. Con6equently, the polym~rization procseds from the inside wall~ of the con~ainer toward the center gradually depleting tbe monomer conc~ntration of the remaining ~olution. The r~action væ~el may b~ rotated ~-at a suitable velocity in ord~r to ev~nly r~di~tr~bute the energy input as well ~ th~ monomer~c ~olution. The unreactive high refractiv~ index guest compound concentration increase~ towards thQ center as th~ polymer matrix formation progresse~ toward the center of the reaction ves~el. ~his result~ in a r~fractive ~nd~x gradient from the periphery to th~ c~nt~r ~xi~ of th2 article produced.
In another preferred embodiment o~ the invention, graded index thermopla~tic pr~form~ produc~d by the method~ of the invention are used to ~anufacturo optical ~ibers. A6 i8 well-known to tho~e ~kill~d in the art, the thermoplastic optical fibQr product i~ u~ually formed by heat-elongation or heat-stretching from a 30-called preform of relatively short and thick d~men~ion~
wherein ths 6tructural components ~nd their distribution are s~t. Th~ much narrower tran~verse dimen~ion~ of thR
final fiber product hav a graded r~fractiv~ index similar and related to that of the preform from wh$ch they are produced.
Th~ optical fiber ~a~ mater~al ~u~ta~l~ for the heat-~tretch production of ~ ~ingl--mod~ pla~tic optical fiber ~ay be applied in any o~ ~ever~l geo~tric ~hapes, th~ prsferred baing cylindrical or rod-lik~. For example, a cylindrical preform tran~mitter having ~
refr~ctive ind~x which gradually decreases radially from a relatively high refractive index value at the center axis region (core) to a relatively low refractive index t i 2~ ~17~
-value at the peripheral region is design~ted as a convex lens-acting optical tran~mitter. Thi~ typ~ of light transmitter i~ preferably usRd to manu~acturs a bar-typQ
lens or ~n optical ~ib~r.
S The polymer m~trix of the ~h~ped nrt~clOEis of the invention are comprised of fluorinated polymers.
Fluorinated compound~ are particularly ~uited a~ polymer optical transmit~rs aince their attenuat~on i8 favorably low at wavelength- about 700 nm, i.~. in the visihle spectrum. Noreover, the l$ght transm~s~ion Or fluorinated polymer optic waYeguide~ i~ clearly in?proveid co~pared with the ~tnte of thei art ~nd with optic waveguides containing poly~ers d~riv~d fro~ monomer units which for the most pArt contain hydrogen atom~. The - 15 optic waveiguides manufactured from theso ~luorinated polymers can ~160 be used in the wavelength range of 850 nm in which high performance luminou~ diodes and semico~ductor lasers ~ well as receivers are available 80 that long transmission distance~ o~ light ~ignals are po~sible.
Fluorinated polymer~ u~erul in the pre~ent invention a~ ~he polymer matrix ~ust hav~ a high glass transition point and high light transmittance. Tho~e iluorinated polymers are preferably used which di~pl~y higher transparency than polymethyl methacrylata (FMMA), a poly~er u~ed in the prior art for the ma~uf~cture o~
optical fibers.
~- 211~ 7~i ~
The initial material for the synthesis of the fluorine-containing polymer ~ay be a co~pound o~ ~or~ula I:
CFX-CF-~~-OR
(I) wherein X is ~ hydrog~n atoD or a deuterium ~tom, and R
is a linear, br~nched or cyclic Cl-C~O alkyl group or a ~-C~O aryl group. Th~ hydrogen ~toms o~ R may b~ complat~lyor partially replaced by fluorin~, chlorin~, or bromlna atoms.
The acid co~ponent o~ th~ est~r~, pr~sr~bly consists of 2,3-dirluoroacrylic ~cid or 3-d~ut~ro-2,3--15 difluoroacrylic acid.
The alcohol compon~nt is pre~erably msthanol, a fluorine or chlorine-containing lin~ar or branchQd or alicyclic alcohol with 2 to 10 carbon atom~ or an arom~tic alcohol with 6 to 10 carbon atoms. Preferred are methanol, chlorine and fluorine containing linear or .
branched, or alicyclic alcohol~ with 3 to 10 car~on ~to~
as well as phenols and benzyl alcohol. Especially preferred are methanol, hexaflu~roi~oprop~nol and 2-deuterohex~fluoroisopropanol, ~lkyl ~nd aryl sub6titut~d hexafluoroisopropanols such as per~luoro-2,3-di~thyl-2-butanol, 2-pent~fluorophenylhexa~luoroisopropanol and 2-(p-fluorophenyl)hexafluoroi~opropanol, ~luorin~-and chlorine-containing cyclopentanol~ and cycl~hexanol~ a~
well as 1,4,5,6,7,7-hexachloro- and hexabro~obicyclohept~nol, 1,4,S,6,7-pentachloro- and 1,4,5,6-tetrachlorobicyclohspt~nol, 5,5,6,6-tetraki~(tri~luoro~ethyl)bicycloh~ptanol, 5,6-difluoro-5,6,-(trifluorom~thyl)~icycloheptanol, 5,5,6,6-tetrafluorobicycloheptanol, 1,4,S,S(or 6,6),7,~-35 hexachloro-6~or -5)oxobicyclooctenol or (1,4,5,6,7,7- :
hexachlorobicycloheptenyl)methanol an~ theix deuterat~d ~. ~
:::
2 ~
derivatives, as well as pentafluoro, pentachloro- and pentabromophenol.
Preferably e~ter~ wherein the hydrogen atoms of the alcohol in the acid component are replaced ~
completely as possible by deuterium, fluorine, chlorine or bromine atom~ are used. Preferred e~ters ar~
methanol-d3, 2-deuterohexafluoro~opropanol, trichloroethanolodl, 3-penta~luoroph~nyl-hexa~luroisopropanol, p~rfluoro-2,3-di~ethyl-2-butanol, perfluoro- or perchlorocyclopentanol or cyclohexanol a~
well as l,4,5,6,7,7-hexAc~loro and -hexabro~obi~ycloheptenol-d~, 5,6-difluoro-5,6-bis(trifluoromethyl)bicycloheptanol-d~, 5,5,6,6-tetrakis(trifluoromethyl)bicyclohept~nol-d~, 5,5,6,6,-tetrafluorobicycloheptanol-d", 1,4,5,5~or 6,6),7,8-hsxachloro-6~0r-5)0~0bicyclooct~nol-d3, or (1,4,S,6,7,7-hexachlorobicyclohepteny~)~ethanol-d5, pentafluorophenol or pentachlorophenol.
It is preferred th~t the hydrogen atom in the acid component, and possibly the hydrogen atom or atom~
in the alcohol component be replaced by on~ or ~or~
deuterium or fluorine atoms since the hydrogen atom~ may i~pair the transparency of the polymers in th~ u~eful vi~ibl~ and in the near-infrared region of th-electromagnetic ~pectr~m.
The 2,3-difluoroacrylic acid ester~ according to For~ula I may ~e ~ynthesiz~d by e~tarirication of 2,3- -dichloro-2,3-difluoropropionic ~cid or a corresponding acid h~lide w$th an alcohol of the formula R-OH, wherQ R
ha~ the meaning given in formula I, and sub~eguænt dehalogenation with zinc. Thq corresponding 3-deutero-2,3-di~luoroacrylic ~cid ester~ 3r6 obtain~d by e~teri~ication o~ the 3-deutero-2,3-difluoroacrylic ~cid or its acid halide w$th an alcohol a~ de~cribed abov~.
In a preferred embodi~ent the poly~r matrix of the shaped articles of the invention may be produced fro~
units derived from one or more e3t~rs o~ formula II~
~X',, 2 1 ~ ~ 7 t~
CYY'~CX-Q OR
(II) where X denote~ a hydrogen or a deuterium atom, C~-C~
alkyl, prefer~bly r~thyl, c.r ~ fluorine atom; Y d~notes a hydrogen or a deut~riu~ atom; Y' denot~ a hydrog-n or a deuterium ~tom; ~nd R is ~ lin~r, branch~d or cyclic C1-Clo ~lkyl group. Th~ hydrog~n atom6 in X, whQn X i~ Cl-C~
alkyl, or ~ may be totally or psrti~lly r~pl~c~d by fluorine atoms.
Suit~ble ~luorinated polymers ar- polym~ric 2- :~
fluoroacrylic acid ~ster~, especi~lly e~ter~ o~ aliphatic alcohol~. Tha~e polymeric material~ ~ay contain deuteriu~ atom~ both in the ~lcohol ~nd ~lso in the ~
po~ition of th~ 2-fluoro~crylic aci~ compon-nt (~ EP
128517). Thes~ polymer~ have indice~ Or r-fraction between 1.45 and 1.60 and glas~ tran~it~on point~ ~tw~Qn loO~ and 200C and thu~ may ~erv~ ~ the polym~r m~trix material for optic wa~e~uides or optic ~ib~rs. Polymeric 2-fluoroacrylie acid esters of ~rominR, chlorin~, fluorine or deuteriu~ containing alcohol~ m~y also b~ - -usQd. ~:
Especially preferred are polymer~ obtain~d essentially from 2-~luoro~crylic acid methyl e~ter3, ~ro~
2-fluoro- and 2,3-difluoroacrylie ~c~d ~ster~
~ethacrylic ~c~d ~st~rs and acrylic acid ~ster~, o~
hexafluoroi~opropanol and 2-d-uterohexa~luoroi~opropanol, 30 alkyl and aryl ~ubstituted h~xa~luoroisoprop~nol~ ~uch ~ ;
per~luoro-2,3-dimethyl-2-butanol,2~
penta~luorophenylh~xa~luoroi~opropanol ~nd 2-(p- -fluorophenyl)h-xafluoroisopropanol, fluor~nQ- and , chlorine-cont~ining cyclopentanol~ and cycloh~xanol~ a~
f 35 well a~ 1,4,5,6,7,7-hexac~loro- and f hexAbromobicyclohept~nol, 1,4,5,6,7-pentachloro- nnd 7 1,4,5,6-tetrachlorobicycloheptenol, 5,5,6,6~
.
:, .. ,. . - : . ,, .. :. ., . . . - ~
2~ ~ ~7'; ~
_~.
lS 1120280-311 totr~kis(tri~luoro~ thyl)bicy~loheptanol, 5,6-dirluoro-5,6-(trifluoromethyl)bicycloh ptanol, 5,S,6,6-te~r~rluorobicycloh~ptanol, 1,4,5,5(or 6,6),7,8-hDYaohloro-6(0r -S)oxoblcyclooct nol or (1,4,5,607,~-S hox~ch~orobicycloh-pt-nyl) tb~nol ~nd th~ir d~ut~rat~d d-rivativea, as ~11 a~ p-nta~luoro, p~nt~chloro- and pen~abronoph-nol.
Pr~r~bly ~t~r~ wh r-in th hydrog n ~to~ o~
th~ ~lco~ol ~n th~ ~ia oo~pon nt ar~ r-plac~d a~
co~plet~ly as pc#sibl~ ~y d~utQrlu~, ~luor~no, chlor~n~, or bro~in~ ar~ uJ-d. Prer-rr~d e~ora ~ro ~o ~ ol-d~ 2-d~utsroh~xaSluoroi~opropanol, tr~e~lorooth~nol-a2, 3-pont~luoroph~y~h~xa~l~oroi~opropRnol, p r~luoro-2,3-~mot~yl-2-butanol, p~r~luoro- or perchlorocyelop~ntanol or eyelo~exanol ~ well ~5 1, 4,5,S,7,7-hu~a~hloro and -hex~bro~obieyelo~pt-nol ~ , 5,6-di~luoro-S,6-bi~(tri~luoro~thyl)bleyeloh pt~nol-d", 5,5,6,~-t~tr~ki~(tr~luo~o~-thyl)bley~loh~pt~nol-dll, 5,S,6,6-t~txa~luorobieyelo~qptanol-dl" 1,4,5,5~or C,6),7,~-h-Y~ehloro-6(or -5)oxo~1eyelooct~nol-d~, or ~ ,5,~,7,7-h-xaehlorobleyelo~ nyl)~o~hanol-~, pon~a~luorophYnol or p-ntaehlorop~nol.
P~ors~d ~olys~rs ~or ~roducing GRIN p~e~o~3s un~ul ~or th~ ~nuSactu~ o~ op~ical ~ib~r~ ar-poly(trifluoro thyl-2 fluoroacryl~t~ poly 3FFA~);
poly-~tri~luoroethyl ~thac~ylat~ poly 3FMa~); ~nd poly-~2-fluors~c2yl~c, hexa~luoroi~opropy~ ~c~d) (~poly HFlP2FAU). 0~ th--J--polyz~--, poly 3FP~ ~ t v~ry ~oluble ln it- ~ono~r rrA ~nd i- th r-rOr- not ~ -rul ln the two-~Sep polynQ~i8at~on proaes~ o~ the ~nv~ntion u~ing t~ ~ir~t ~top preparation o~ tb0 ~ladding tubQ.
P~ly-3F~A ~nd ~oly ~FIP2~A ~r- ~olubl- in th ~r ~cno~er~
and thu~ u~ful in kDtb n thods o~ th~ in~Qnt~on. The preferr~d 2-~luoroacrylic acid ~onomer i~ 2-~l~o~o~crylic acid h-x~luoroi~opropy~l t~r (~F~n FA~).
Sub~tantially unr~acti~ fl~al~ gu~t ~olecul-~ar~ understood to include low ~ol~cula~ wsig~t coypoun~s ~.,r''' ' '" ' '' '' ' '~' ' "' - " ~' , '' ':
21~ l7~1 w~ich do not polymerize with the basic mono~ers or polymeric ~atrix. It i~ presumed that t~e ~mall molecules do not react radically within the condition parameters prevailing during the gel formation and post polymerizati~n treatment. Typically, the low ~olecular weight guest compounds are selected from certain high refraction index ~liphatic~l; or alkylaromatics, which may be optionally substitute~ with, ~.g., ~alogen atom~ and prQfer~bly fluorinQ atom~. The gu~t molQcul~ o~ cour~e must be selected so that it i~ optically compatible with the particular polymer ~ystem o~ the ~hap~d article.
Suitable ~mall molecule~ may ~e selectQd from, but not limited to, the group o~ dibutyl phth~late, benzyl benzoate, butyl phenyl phthalate, benzyl-n-butylphthalate, 1-methoxyphenyl-1 phenyl ethane, 3-phenyl-1-prop~nol, bromo~enzenQ, m-dichlorob~nzene, 1,2-dibro~oethane, o-dichlorobenzene, bis(1,1,1,3,3,3 ~-hexafluoroisopropyl)terephthalate, and other halogenated or, preferably, ~luorinated aromatic~.
In a preferred embodiment of the invention the small guest molocule is a molecule of the formula III:
O
~ ont ;
l (III) OR ~ .
O
wherein Rf is C~-C~0 ~l~yl, C~-C,0 aryl or a parti~lly or fully halogenated C~-C,0 alkyl or ~-C,0 aryl group.
~ he production and propertie~ of the poly-(2-fluoroacrylic acid fluoroalkyl ester~) are known in the art (~ee EP 128516). Polymerization of ~ono~er~ i~
conducted in ~olution or suspension by radical initiation in the presence of a chain-transfer agent at a temperature approximately between 0 and 100C.
.~ ; 2 1 ~
The polymer matrix compound can option~lly be produced by free radical poly~erization in solution in the presence of ~n initiator. Suit~ble radically ~cting initiators u~eYul in uch polymerization~ ar~ azo compounds ~uch ~ azo-bi~-$~o~utyron$trile, azo-~e-(cyclohexylcarbonitril~), azo-bi~-(t-octane), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile ~nd organic peroxide~ ~uch ~ t-butyl poroxide, t-butyl peroctanoate, t-butyl peroxyi~opropylcarbonate, t-butyl hydropero~ide, t-butyl peroxyisobutyrate, and dicumyl peroxida. The guantity of the initiator lia~ $n th~ range ~rom 0.001 to 3.0 moles, pre~erably 0.036 to 1.0 mol~ per 100 moles o~
mono~er.
The polymerization may also take place in the presence of a chain tran~fer medium (regulator or agQnt)_-Especially suitable ~or this ar~ ~ercaptans such as n- or t-butyl mercaptan, propyl mercaptan, phenyl mercaptan, t-hexyl mercaptan and butylen~-1,4-dithiol a~ well a~
esters of mercaptoacetic acid, ~.g. mQthyl-mercaptoacetate, ethylene glycol-bi~(mercaptoacetate).
The polymarization temperaturs ~hould ~Q in the range of 20 to 180-C, pre~erably 40 to 160C, ~nd mor~
preferably 60 to 140C.
It i8 racommended that the mixture be degassed before polymerization. For thi5 purpos~ th~ reaction mixture of monom~r, unreactive ~mall ~olecul~, one or more initiator~ and regulator~ ir~t cooled in a reactor to a temperature o~ at lQa~t -80~C, th~n the reactor is ev~cuated and warmed in the clo~ed ~tat~ to a ~emperatur~ of 0 to 25~C. ~hi~ proce~ is pre~rably repeated eeveral times. Altarnati~ly, th~ reaction mixture may hav- ~ stream o~ hydrogen, heliu~, ~rgon or nitrogen gas which ie pas~d down to th~ ~loor o~ th~
reactor through ~n i~m~r~ed ga~ pipe for ~ period o~ ~ 1 to 60 min, pref~rably 5 to 30 min.
2~1~ 7~
lB 1120280-311 FABRICATION METHODS
One general methodology use~ul to make preforms and optical ~iber in accordanc~ wi~h th~ pre~cnt invent~on i~ de~crib~d in U.S. Pat~nt No. 4,521,351.
Referring to F~g~ nd 2, a ~ono~eric ~ix*ure of the ~no-2r and ~all gue~t mol-cul6 ~ fill~d ~n glas~ tube 4 having a closed end and an in~de di~met~r of about 3 ~ to abo~t 10 J~. A tubular ultrnv~olet lamp 1 is located centrally ~n t~e ~pparatu~, and a cylindrieal light-shielding plate 2 i~ ~ecured to each o~
the upper and lower section~ of the l~p 1 80 tha~ the ~ 15 mixture in th~ gla~s tube 4 i6 $rradiated only by ultraviolet light relea~ed ~ro~ th~ centr~l portion o~ `
the tu~lar la~p. ~ collar-lik~ auxiliary light-~hielding plate 11 i~ provided ~o that the light from the la~p 1 i6 releas~d only in~o ~ pace between the light shielding plate~ 2 ~for ~xa~ple~ 70 mm). The i~ten~ity of ultraviolet light i~ ~onitored by a ~ilicon photocell ~ :
3. The intensity Or the ultr~violet ligh~ i6 pre~erably maintained con~tant during polymerizat~on. A plurality of glass tubes 4 filled with the monomeric ~ixture are ~ounted on a ~upport ~e~ber 5 at a predeter~ined dii3tance, for ~xAmplQ 10 cm, from t~e ultraviolst la~p 1, and rotated at ~ isp~ed o~, ~or xampl~, 40 rpm by ~ ~otor 6. Initially, thQ ultraviolet la~p, for cxampl~ 00 W
lamp, ii~ placed ~t ~ position lower th~n the lower ~nds of the gla~ tubei~ 4, ~nd ultraviol~t l~ght i~ irr~diat~d onto thc glass tub~s 4 whil~ thc l~mp 1 iB moved upwardly by a ~otor 7 ~t a pr~d~ter~ined rat~ o~, for ~xampl~, 0.3 to 3.0 ~/min. Air 2t a fix~d temperatur~ Qn~ in~o the apparatu6 by æ ~n 9 ~rom ~n ~nl~t 8, ~nd di~charged ~ro~ a discharg~ op~ning 10. ~he temperature o~ the inside of th~ apparatu3 rise~ duQ to the generation o~
heat from the lamp 1, but beco~e~ constant nt f l 2~ 7l~
temperature 60me degrees higher than the temperature o~
the air current.
Photopolymerization by a ~ree r~dic~l mechanism 6tart~ at the outside portions Or the bottoms oS ~he 5 glass tube~ 4 which re ~irst expo~ed to ultraviol~t radiation. Volume shrinXag~ ~Ay occur du~ to polymerization. But ~inc~ unr~ac~d mono~eric ~ixture is fed ~rom that part ~n th~ uppar ~ction o~ ~ach o~ th~
glass tube~ wh$ch has not yet und~rgon- ultraviol~t 10 irr~diation, no space ls formod inside th~ polymor matrix.
With ~he ~ovement of the lamp 1, polymerization proceeds gradually upward until all of the monomer$c 8 miYture in each glass tube 4 i8 601idifiRd. After the ;~
15 lapse of a predetermined per$od o~ time from the start of irradiation, for ex~mple a~out 10 hour~, th~ ultraviolet irradiation iB stoppQd, and th~ gla~ tubes 4 ars removsd from the apparatus. Th~ gla~E tube~ ~ay then b~ heated to a temperatur~ ~ufficient to polymeri2~ the remaining 20 mono~ers as completely as pos~ibl2. ~hi~ temperature dependent on the type of poly~er ~y~tem being u~ed, an~
should preferably be a te~peratur~ above that o~ the interior of the poly~erization apparatu~.
Aft~r polymeriz~tion i5 co~pleted, the gla~s 25 tubes are crushed, and the prefor~ rod~ are taken out.
Each of th~ rodQ show a fixed re~ractiv~ index distribution exc~pt at the ~nd portlnn~. Light-converging fib~r~ can b~ obtained ~y h~ating ~nd stretching e~ch of the re~ulting rod~ (light-tran~mi~ting 30 elements~. It i~ recom~ended that prior to heating and strQtChing 0~ thQ rods, the rods ar~ left to ~tand under a reduced pre~uræ of 10~ to 101 ~m~g at 50-C for 3 to 4 days in order to remove trace~ o~ volatil~ substances contained in the rod~. The post tr~at~ent may al~o apply 35 a heat-6hrinXing tube whereby bubble for~ation i~
suppressed.
- ' 2~ fi~
Fiy. 3 ~hows a heat-drawing apparatu~ ~howing the principle on whic~ the rods are ~e~t-drawn into optical fiber~. Typic~lly ~ rod o~ 1~88 th~n half a meter in length i8 mounted on a ~upport ~ember 22, and S then allowed to desc~nd vQry ~lowly at a velocity V~
(mm/~ec), pas6ed betwaen h~aters 23 ~t ~ *ix~
temperature Td, and pulled ~nd stretched ~t ~ groat~r velocity o~ V2 ~m/~ec by a driv~ roll 24 h~low.
The ~ollowing ~xa~pl~ p~rtain to sdvantageou~
use of certa~n ~luorinated homopolymQrs in ~ccordancQ
with the present invention where$n th~ h~gh refraction :
index monomer or small molecules ~re di~tri~ut~d a~
refractive components in a gradient ~rom th- core to the cladding portion of the optical fiber.
~ , Monomeric mixture for ~roduct~on o~ P3FMA tub~:
Poly(tri~luoroethyl methacryl~t~) graduatod index plastic optical ~iber (P3FMA GRIN POF) was produced as follows:
(a~ Preparation o~ ~ube/claddina.
A monomer mixture co~pri~ing 3FMA gl,l,1-trifluorosthyl methacrylate) monomer with the addition of ~enzoyl peroxide (BPO), 0.5 wt~ (weight percent), as an initiator; n-lauryl mercaptan 0~1 wtt a~ a chain trans~Qr ag~nt wa~ pr~par~d. Th~ mixtur~ wa~ plac~d in a gla~
tube with a 20 ~m inner diamater. A~t~r being ~al~d on oppo6it~ end~, thQ gla~s tuba wa~ placed ~or ~er~al polymerization of the monomer~c DixtUr~ horizont~lly in furnace at 70C.
The tube was rotat~d a~out ~ts cent-r ~xic at 2000 rpm ~or a polym~rization tima of about 20 h. ~f~r polymerization the outer glas~ tube was broken and removed. The outer ~nd inner diamet~r o~ the P3FNh tub~
product or cladding wa~ 20 mm ~nd 1~ m~, re~p~ctively.
- , - i .. . . , ., , .. ,-, . ~ .
- i 21~17~; ~
(h) Preparation of GRXN_~re~or~ rod:
A monomeric mixture COmpriBing 3FMA monomer ~nd the 6ubstantially unreactive small molecule, Dibutyl phthalate (DBP), in ~ 3FMA/DBP w~ight rat~o o~ 5/1; with S the addition of 0.5 wt%~ Bis tt-butylp~roxy)3,5,5-trimethylcyclohexan~ (PH3M) ~ initiator; And 0.1 wt% n- -lauryl mercaptan as cha~n transf~r ag~nt W~8 prep~r~d.
ThQ P3FMA tubs producsd ~n ~tep (a) was filled with the monomer ~xturQ and ~al~d, thQn placQd horizontally in a ~urnaco ~t 95-C. for thermal polymerization while rotating at a~out 30 rpm. ~h-polymerization time was about 24 h.
As a post-tr~atment, the preform rod was heat- -treated at 100C under about 0.2 mm ~g atmosphers for 24 h. The resulting polymer had a content o~ residual unreacted monomer of 0.5 wt.% or less. The eladding and core portions were thus integrated into a monolith.
(c) Preparation of GRI~ F~F:
After th- GRIN preform monolithic rod wa~ cut at opposite end~, the pref~r~ rod was heat-dr~wn at 200C. to form an optical fiber of ~bout 0.6 mm diameter.
A refractive index distribution of the preform (shown in Fig. 4) was measur~d by the int~rfero~Qtric technique.
(d) Optical P~o~ertv o$ the P3FMA GRIN POF
The bandwidth of the G~IN POF wa~ mea~ur~d ao follow~
A pulse of 10 M~z ~rom a lAser diode (InGaAlP;
wavelength ~670 n~) was introduced (N.A.-0.5) ~nto ~ 40~
long sampl~ fib~r. The output puls~ w~ d~tected by ~-6ampling hend (mod~l OOS-Ol, Hamamat~u Pbotonic~ Co.).
The result i~ 3hown ln FigO 5. Th~ bandwidth 3S was estimated from the 3d8 level in impulee respan~e ~u~ct~o~
'` . ~ 2~ ~17~
:
The bandwidth of the 40 m ~iber length o~ ~3FMA
GRIN POF with the FWHM (~Pull width at half maximum~) of the input pulse at 80.5 ps and output at ~7.5 p~. was 632 - MHz/k~. ' A total attenuation pectrum of th~ GRIN POF ~ 8 shown in Fig. 6.
S~NP~ 2.
A GRIN POF utilizing a ~luorinated monomer ba~e prepared as described in thi~ example at a diameter of 0.6mm exhibited the following op~ical characteriza~.'.ion.
The attenuation of transmis~ion at 780 nm w~velenqth w~
found to be about 200 dB/km and apparently much low~r ~han that of comparatively preparsd ~ethyl methacrylate (MMA)-base GRIN POF (700dB/k~
~ he cladding material was compo~ed of the pure homopolymer, poly~FIP2FA). The advantnge o~ ~uch a compo6ition i~ that ther~ i3 no need to U8- ~ highly perfluorinated cladding ~aterial wlth the concomitant disadvantag~ of low optical clarity and crystallinity.
(a) Preparation of HFIP2F~ tube eladding:
A mo~omer mixtur~ compr~ing HFIP2FA monomer, 0.06 wt.~ of Benzoyl peroxide ~BPO) a~ ~n initiator and 25 0.10 wt.% o~ n-lauryl mercaptan a~ a chain transfer agent -~ ~
was prepared. The mixture wa~ placed in a gla~ tuhe -.
with a lOmm inner di~met~r, ~ tu~e cladding wa~ produced .
by th- method of ExamplQ l(a), abov~.
The mixture was placed in a gla36 tubQ with 10 mm diameter, bo~h end~ wera ~ealed ~nd tha gla~ ~ub~
wa~ plac~d hor~zontally in ~ furn~c~ ~ in the ~ethod oP
Exa~pia l(a). The tub- was rotated about it~ axia at -:
1000 rpm at 70DC ~or about ~0 h. Th~ out~r and ~nn~r ~ -diameters o~ the resulting HFIP2FA polymer cladding tu~e were approximately 10 m~ and 6 mm, re~pectiv~ly.
2~7fi~
(b) ~reparation_o~ ÇRI~ ~xefor~ Rod.
A monomer mixture eomprising HFIP2FA monomer with Dibutyl phthalate (DBP) ac th~ unreactive ~mall ~olecule component in ~ ~FIP2FA/D~P weight r~t~o o~ 10/1, with O.2S wt% t-Butyl peroxy ~sopropylcarbonatQ (~PPC) (fro~ Nippon Oil And Fats Co.) a~ in~tiator, and 0.10 wt.% n-lauryl ~erc~pt~n as the chain ~ransfer ~gent wa~
prepar~d. The polymerlzation temperatur~ of the ~ixture iR 95C.
~he tu~e cladding wac pla~ed within a hoat shrink tube (FEP-090 from Plon Rogyo Co.), ~illed with ~ono~er mixtur~ sealed and pl~ced in ~ furnace. A~ter A
20 h polymerization at the mixture polymerization temperature with rotat~on, each preform rod with heat shrlnk tube was heat treated at 110C under normal pressure for one day followed by a heat treatment without - the heat-shrink tube at 1l0CC for 20 h under ~ pressure of 0.2 ~ ~g.
(c) PreDaraticn of GRIN POF~
The GRIN POF wa3 obta~ned by the heat drawing of the above GRIN preform rod~ at 200-220C. The optical :~
fiber obtained w~ 0.6 mm ln diameter ~nd 50 m long.
Following polymerization of the tube claddin~
25 the tube had a ~lightly yellow coloration rend~ring it --~
less desirabl~ for ~anufacture of optical fib . ~ub~
cladding produc~d under Example 3 b¢low wa~ transpar~nt and usQd to produce optical ribere with tha low~t ~ -attenuation. :~
pXAMP~J 3 . To reduca the for~ation Or color, it ~a ~ound that the i~itiator azobi~i~obutylonitrile (AIBN~ could be substituted for benzoyl peroxid~ in ~h~ procsdure of ~.
Exa~ple 2 and the polymerization temperature reduced.
Specific for~ulations were~
21~ ~.7~
(a) Tube Claddin~:
~ono~er: HFIP2FA, Initiator: 0.05 wt% AIBN
Chain ~ran~fer agent: 0.15% n-lauryl m~rcaptan;
(b) Prep~ration of Preform Rod:
~onomer: HF~P2FA, U~reactivQ Component: dibutyl p~talat~ (DBP), Feed ratio of 10/1, HFIP2FA/D8P, Initiator: AIBN 0.07 wt~
Claim transfer agent: 0.10% n-lauryl merc~ptan Polymerization Temperature: 65C.
O~tical pro~erties:
The opt~cal fiber of Exa~ple 3 exhibited a lower attenu~tion than that o~ Ex~mpl~ 2. A r~ractivQ
index distribution of the preform of Exampl~ 3 wa~
measured by the trAnsv~r~e interferom~tric t~chnique.
The total attenuation spectrum of the GRIN POF of Example 3 is shown in Fig. 8. The ~inimum attenuation of transmission i~ only 209.1 dB/~m ~t 780nm wavelength measured incidentally with ~ commercially available Laser Diode. ~n contrast, the attenu~tion number~ of P~MA-~ased and 3FMA-based GRIN POF at 780 nm are about 700 dB/km and 400 d~/km, respectively.
XAMP~ ~
Following the procedure of ~xample 2 ~ GRIN ~OF
fiber ~ay be prepar~d using ~ ~onomer of the ~tructural formul~ IV:
C
Il - ~r5 for both tube cladding and cor~ of the preform.
2~7~1 , ~ , .
~AMP~_S
Following the procedure o~ Example 2 a GRIN POF
fiber may be prepared using a monomer of the structural formula V: F
s a-~=c Il--~all-cc for both tube cladd$ng ~nd cor~ o~ the preform.
Claims (23)
1. A monolithic thermoplastic article comprising a fluorinated polymer component and a substantially inert low molecular weight guest molecule component, which guest molecule component is substantially unreactive with the polymer component but soluble therein and exhibits a refractive index different from that of the polymer component; and wherein the concentration of the guest molecule component within the article exhibits a concentration gradient from the center to the periphery of the article defined during the formation thereof so that the article exhibits a graduated refractive index dependent from the concentration gradient from the center of the article to the periphery of the article, the graduated refractive index at the center being different from that at the periphery.
2. The monolithic thermoplastic article of claim 1, wherein the low molecular weight guest molecule component has a refractive index about 0.001 units higher than that of the fluorinated polymer component.
3. The monolithic article of claim 1, wherein the low molecular weight guest molecule component has a refractive index about 0.005 units higher than that of the fluorinated polymer component.
4. The monolithic thermoplastic article of claim 1, wherein the concentration of the substantially unreactive low molecular weight guest molecule component is from about 1% to about 20% of the weight of the article.
5. The monolithic thermoplastic article of claim 1 wherein the article is in the shape of a cylindrical preform and is useful in the manufacture of optical fibers.
6. The monolithic article of claim 1, wherein the article is an optical fiber.
7. The monolithic thermoplastic article of claim 1, wherein the fluorinated polymer comprises a monomer having a formula (I):
(I) where in X is a hydrogen atom or a deuterium atom and R
is a linear, branched or cyclic C1-C10 alkyl or a C6-C10 aryl.
(I) where in X is a hydrogen atom or a deuterium atom and R
is a linear, branched or cyclic C1-C10 alkyl or a C6-C10 aryl.
8. The monolithic thermoplastic article of claim 6 wherein the hydrogen atoms in R are partially or completely replaced by fluorine, chlorine or bromine.
9. The monolithic thermoplastic article of claim 1 wherein the fluorinated polymer comprises a monomer having a formula (II):
(II) wherein X is hydrogen, deuterium, fluorine or a C1-C6 alkyl group, Y is a hydrogen atom or a deuterium atom, Y' is a hydrogen atom or a deuterium atom, and R is a linear, branched or cyclic C1-C10 alkyl group.
(II) wherein X is hydrogen, deuterium, fluorine or a C1-C6 alkyl group, Y is a hydrogen atom or a deuterium atom, Y' is a hydrogen atom or a deuterium atom, and R is a linear, branched or cyclic C1-C10 alkyl group.
10. The monolithic thermoplastic article of claim 8 wherein the hydrogens of X, when X is C1-C6 alkyl, or the hydrogens of R are totally or partially replaced by fluorine.
11. The monolithic thermoplastic article of claim 1 wherein the fluorinated polymer is poly-(trifluoromethyl methacrylate) or poly-(hexafluoroisopropyl 2-fluor-acrylate).
12. The monolithic thermoplastic article of claim 1 wherein the low molecular weight guest molecule component is a molecule of the formula III:
( III) wherein Rf is C1-C6 alkyl, C6-C10 aryl or a partially or fully fluorinated C1-C6 alkyl, or a partially or fully fluorinated C6-C10 aryl group.
( III) wherein Rf is C1-C6 alkyl, C6-C10 aryl or a partially or fully fluorinated C1-C6 alkyl, or a partially or fully fluorinated C6-C10 aryl group.
13. The monolithic thermoplastic article of claim 1, 6 or 8 wherein the low molecular weight guest molecule component is selected from the group consisting of dibutyl phthalate, benzyl benzoate, butyl phenyl phthalate, benzyl-n-butylphthalate, 1-methoxyphenyl-1 phenyl ethane, 3-phenyl-1-propanol, bromobenzene, m-dichlorobenze, 1,2-dibromoethane, o-dichlorobenzene, bis (1,1,3,3,3, .alpha.-hexafluoroisopropyl)terephthalate, or a fluorinated aromatic compound.
14. The monolithic thermoplastic article of claim 10 wherein the low molecular weight guest molecule component is dibutyl phthalate.
15. A process for the production of a monolithic fluorinated polymer based article having a graduated refractive index from its center to its periphery comprising; polymerizing in a suitable vessel a fluorinated monomer in the presence of and in solution with a substantially unreactive, low molecular weight guest molecule which is soluble in the monomer and polymer, and which has a different refractive index from that of the fluorinated polymer; by initiating the polymerization of the monomer at the surface of the vessel and allowing it to proceed at a controlled rate so that the guest molecule component forms a concentration gradient within the article as the polymerization progresses from the periphery to the center of the article to form a monolithic article with the refractive index being radially graduated from the center to the periphery.
16. The monolithic fluorinated polymer based article produced by the method of claim 15.
17. A polymer optical fiber exhibiting low optical dispersion and high bandwidth formed by polymerizing a fluorinated monomer to form a matrix polymer in the presence of an optically compatible, substantially unreactive low molecular weight guest molecule having a higher refractive index than the matrix polymer formed from the fluorinated monomer, wherein the concentration of the guest molecule in the fiber is defined by a concentration gradient which is greater at the center of the fiber than at the periphery, the fiber having a graduated refractive index profile defined radially by the relative concentration ratio of the polymer and the substantially unreactive low molecular weight guest molecule, with the center having higher refractive index than the periphery.
18. The optical fiber of claim 17, wherein the fiber exhibits a low overall light attenuation effect, dB/km, ranging from about 200 to about 400.
19. The polymer optical fiber of claim 17 wherein the low molecular weight guest component is fluorinated.
20. The polymer optical fiber of claim 17 wherein the monomer is partially deuterated.
21. The polymer optical fiber of claim 17 wherein the matrix polymer is a polymeric 2-fluoroacrylic acid ester.
22. The polymer optical fiber of claim 17 wherein the matrix polymer is poly(trifluoroethyl methacrylate) or poly(hexafluoroisopropyl 2-fluoroacrylate).
23. The polymer optical fiber of claim 17 wherein the guest molecule is dibutyl phthalate.
Applications Claiming Priority (2)
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US99393592A | 1992-12-18 | 1992-12-18 | |
US07/993,935 | 1992-12-18 |
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CA002111761A Abandoned CA2111761A1 (en) | 1992-12-18 | 1993-12-17 | Shaped articles of graduated refractive index exhibiting low dispersion |
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EP (1) | EP0606598A3 (en) |
JP (1) | JPH08510763A (en) |
KR (1) | KR940014545A (en) |
CN (1) | CN1103954A (en) |
BR (1) | BR9305114A (en) |
CA (1) | CA2111761A1 (en) |
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WO (1) | WO1994015005A1 (en) |
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US5760139A (en) * | 1994-04-18 | 1998-06-02 | Yasuhiro Koike | Graded-refractive-index optical plastic material and method for its production |
ES2191050T3 (en) | 1994-04-18 | 2003-09-01 | Yasuhiro Koike | RESIN OF OPTICAL USE OF THE TYPE OF DISTRIBUTION OF REFRACTION INDEX AND THE PROCEDURE OF PRODUCTION OF THIS RESIN. |
JP3719734B2 (en) * | 1995-04-28 | 2005-11-24 | 康博 小池 | Plastic optical fiber cord and bundle fiber |
EP0752598A1 (en) * | 1995-06-09 | 1997-01-08 | Yasuhiro Koike | Graded-refractive-index optical plastic material and method for its production |
US6086999A (en) * | 1997-06-12 | 2000-07-11 | Boston Optical Fiber, Inc. | Method for producing a graded index plastic optical material |
CN1112594C (en) * | 1997-10-02 | 2003-06-25 | 旭硝子株式会社 | Refractivity distributing optical resin material |
JPH11200139A (en) * | 1998-01-20 | 1999-07-27 | Daikin Ind Ltd | Thermally melting fluorine resin fiber |
US6776932B1 (en) | 1998-06-12 | 2004-08-17 | Getronics Wang Co. Llc | Polymeric optical articles |
TWI275471B (en) * | 2002-03-12 | 2007-03-11 | Yasuhiro Koike | Non-birefringent optical resin material and manufacturing method of the same |
JPWO2003091772A1 (en) * | 2002-04-25 | 2005-09-02 | 旭硝子株式会社 | Plastic optical fiber |
JP2006330190A (en) * | 2005-05-24 | 2006-12-07 | Fujifilm Holdings Corp | Plastic optical fiber preform and its manufacturing method |
US9731456B2 (en) | 2013-03-14 | 2017-08-15 | Sabic Global Technologies B.V. | Method of manufacturing a functionally graded article |
CN105196665A (en) * | 2015-09-02 | 2015-12-30 | 铜陵翔宇商贸有限公司 | High frequency copper-clad plate manufacturing method |
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US3718383A (en) * | 1971-04-19 | 1973-02-27 | Eastman Kodak Co | Plastic optical element having refractive index gradient |
US3816160A (en) * | 1971-04-19 | 1974-06-11 | Eastman Kodak Co | Method of making a plastic optical element |
IT1153311B (en) * | 1982-10-27 | 1987-01-14 | Montedison Spa | LIGHT CONDUCTIVE MANUFACTURING PROCESS |
US4521351A (en) * | 1983-01-27 | 1985-06-04 | Nippon Sheet Glass Co., Ltd. | Process for producing light-transmitting element of synthetic resin |
EP0472384A3 (en) * | 1990-08-16 | 1992-10-28 | Yasuhiro Koike | Plastic optical fiber and its manufacturing method |
DE69230524T2 (en) * | 1991-10-22 | 2000-05-18 | Yasuhiro Koike | OPTICAL FIBER WITH BREAKING INDEX DISTRIBUTION AND METHOD FOR PRODUCING IT |
JPH05181022A (en) * | 1991-12-26 | 1993-07-23 | Nippon Petrochem Co Ltd | Light transmission body made of synthetic resin and production thereof |
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- 1993-10-14 WO PCT/US1993/009810 patent/WO1994015005A1/en active Search and Examination
- 1993-10-14 JP JP6515126A patent/JPH08510763A/en active Pending
- 1993-12-15 EP EP93120176A patent/EP0606598A3/en not_active Withdrawn
- 1993-12-17 CA CA002111761A patent/CA2111761A1/en not_active Abandoned
- 1993-12-17 BR BR9305114A patent/BR9305114A/en not_active Application Discontinuation
- 1993-12-18 CN CN93119911A patent/CN1103954A/en active Pending
- 1993-12-18 KR KR1019930028493A patent/KR940014545A/en not_active Application Discontinuation
-
1994
- 1994-01-12 TW TW083100213A patent/TW261669B/zh active
Also Published As
Publication number | Publication date |
---|---|
JPH08510763A (en) | 1996-11-12 |
EP0606598A3 (en) | 1995-03-15 |
WO1994015005A1 (en) | 1994-07-07 |
BR9305114A (en) | 1994-06-28 |
EP0606598A2 (en) | 1994-07-20 |
CN1103954A (en) | 1995-06-21 |
TW261669B (en) | 1995-11-01 |
KR940014545A (en) | 1994-07-18 |
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